ObjectiveTo investigate the effect and underlying mechanism of the Wulao Qisun prescription on pathological new bone formation in ankylosing spondylitis （AS）. MethodsSynovial fibroblasts were isolated from the hip joints of AS patients and observed under a microscope to assess cell morphology. The cells were identified using immunofluorescence staining. The isolated AS fibroblasts were divided into blank group， low drug-containing serum group， medium drug-containing serum group， high drug-containing serum group， and positive drug group. After drug intervention， cell proliferation was measured using the cell counting kit-8 （CCK-8） assay to observe fibroblast growth and determine the optimal intervention time. Alkaline phosphatase （ALP） activity was measured using the alkaline phosphatase assay. Protein expression of osteocalcin （OCN）， osteopontin （OPN）， and runt-related transcription factor 2 （Runx2） was detected by Western blot. The mRNA expression levels of Wnt5a， β-catenin， and Dickkopf-1 （DKK-1） were measured by real-time quantitative polymerase chain reaction （Real-time PCR）. ResultsCompared with the blank group， each drug-containing serum group of Wulao Qisun prescription and the positive drug group inhibited the proliferation of AS fibroblasts and reduced ALP expression （P<0.01）. Compared with the blank group， the low drug-containing serum group of Wulao Qisun prescription downregulated β-catenin mRNA expression （P<0.05）. The medium and high drug-containing serum groups and the positive drug group significantly downregulated Wnt5a and β-catenin mRNA expression （P<0.05， P<0.01）， with the positive drug group showing the most pronounced effect （P<0.01）. The high drug-containing serum group and the positive drug group significantly upregulated DKK-1 mRNA expression （P<0.01）. Compared with the blank group， the low drug-containing serum group of Wulao Qisun prescription inhibited the expression of OPN and Runx2 proteins （P<0.05， P<0.01）， while the medium and high drug-containing serum groups and the positive drug group inhibited the expression of OCN， OPN， and Runx2 proteins （P<0.05， P<0.01）. ConclusionThe Wulao Qisun prescription can inhibit the proliferation and osteogenic differentiation of AS fibroblasts， thereby delaying the formation of pathological new bone in AS. The possible mechanism involves the regulation of Wnt/β-catenin-related gene expression， further inhibiting the transcription of downstream target genes.

Psoriasis is a chronic inflammatory skin disease with a polygenic genetic background. Its etiology remains unclear， and its pathogenesis is complex and refractory， collectively posing significant challenges in its treatment and greatly affecting the physical and mental health of patients. With the advantages of multi-target and multi-pathway treatment， traditional Chinese medicine has shown unique efficacy and value in the diagnosis and treatment of psoriasis. Modern doctors have a lot of discussion on psoriasis， and most of them tend to treat the disease by solving disorders of the blood system. They think that the disease is closely related to the "heat in the blood". Combining the clinical characteristics and accompanying symptoms of psoriasis， this article traced the causes of "heat in the blood" in psoriasis and believed that multiple internal and external factors have prevented the smooth circulation of Qi. Yang Qi Fuyu （stagnation） and transformation into heat and toxicity is the source of "heat in the blood" in psoriasis. Furthermore， it was proposed that "Fuyu" is the core pathogenesis of psoriasis. The etiology of "Fuyu" is complex， such as external wind and cold pathogens， emotional injuries， internal accumulation of dampness， and deficiency of healthy Qi， all of which can disrupt the ascending and descending movement of Qi， impede the circulation of Qi and fluids， close the pores and skin texture， and subsequently lead to stagnation. Based on the above understanding， "resolving stagnation" is crucial for treating the disease. Many doctors have explored the treatment ideas of psoriasis from the perspectives of dispelling wind， warming cold， regulating Qi， eliminating dampness， tonifying deficiency， and external treatment， aiming to remove the causes， promote the circulation of Qi and fluids， and resolve stagnation and heat. Clinical studies have shown that the therapies can relieve clinical symptoms， reduce recurrence rate， and improve quality of life， which also have good safety in the treatment of psoriasis. This article discussed the treatment of psoriasis from the perspective of "Fuyu"， enriching the understanding of TCM regarding the etiology and pathogenesis of psoriasis. It is aiming to serve as an effective supplement to the "treating by solving disorders of the blood system" approach and provide a reference for clinical diagnosis and treatment of psoriasis.

ObjectiveTo explore the effects of Kaixuan Jiedu core prescription （KXJD） on sphingolipid metabolism in the mouse model of imiquimod-induced psoriasis-like skin lesions. MethodsThirty-seven male C57BL/6J mice were randomly assigned into five groups： healthy control （n=11）， model （n=11）， methotrexate （MTX， n=5）， low-dose （15.21 g·kg^-1） KXJD （n=5）， and high-dose （30.42 g·kg^-1） KXJD （n=5）. Psoriasis-like skin lesions were induced in mice with 62.5 mg 5% imiquimod cream applied on the back. The KXJD groups and MTX group were treated with 0.2 mL corresponding decoction and MTX， respectively， by gavage daily， while the other groups were given an equal volume of normal saline by the same way. After 5 days of treatment， back skin lesions were collected. Firstly， healthy control and model mice were selected for tandem mass tag （TMT） quantitative proteomics （control vs model=3 vs 3） and targeted lipid metabolomics （control vs model=11 vs 11）. Then， the binding degree between core components and target proteins was predicted via network pharmacology and molecular docking. Finally， an animal experiment was performed to decipher the specific regulation mechanism of KXJD on sphingolipid metabolism. Immunohistochemistry was employed to determine the expression level of sphingosine-1-phosphate （S1P）， and Western blot was employed to determine the expression levels of sphingosine kinase 2 （SPHK2） and monocyte chemotactic protein-1 （MCP-1）. ResultsTMT proteomics and targeted lipid metabolomics suggested that sphingolipid metabolism was active in the psoriatic skin， and key proteases ［serine palmitoyltransferase， long chain base subunit 2 （SPTLC2）， SPHK2， delta（4）-desaturase sphingolipid 1 （Degs1）， and ceramide synthase 4 （CerS4）］ and 8 sphingolipid metabolites （including ceramides， sphingol， sphingomyelin， and glycosphingolipid） expressed abnormally （P<0.05） compared with those in the healthy skin. The molecular docking results indicated that the binding energy between the active components （quercetin， kaempferol， and luteolin） in KXJD and key proteins involved in sphingolipid metabolism was less than-8 kal·mol^-1. Further experimental verification showed elevated expression levels of SPHK2， S1P， and MCP-1 in psoriatic skin compared with healthy skin （P<0.05）， and KXJD down-regulated the expression levels of SPHK2， S1P， and MCP-1 compared with the model group （P<0.05）. ConclusionThis study indicates that there is an imbalance in sphingolipid metabolism in psoriatic skin lesions. KXJD may reduce psoriasis-like lesions in mice by regulating sphingolipid metabolism via the SPHK2/S1P/MCP-1 pathway.

ObjectiveTo use bioinformatics technology to screen the molecular patterns and diagnostic biomarkers of ferroptosis closely related to psoriasis， observe the therapeutic effect of Kaixuan Jiedu core prescription on psoriasis and explore its potential mechanism through animal experiments. MethodsPsoriasis microarray data from GEO were analyzed to identify differentially expressed genes （DEGs）. Intersection with a ferroptosis gene set yielded psoriasis ferroptosis-related genes （FRGs）， which underwent correlation， consensus clustering， enrichment， and immune infiltration analyses. Core diagnostic FRGs （Hub-FRGs） were identified using random forest （RF）， support vector machine （SVM）， LASSO regression， Nomogram， and ROC analyses. In vivo， imiquimod （5% cream） induced psoriasis in mice （except controls）. Drug treatment groups received respective doses， while control and model groups received saline via daily gavage for 7 days. Back skin changes were recorded and PASI scored. Hematoxylin-eosin （HE） staining assessed histopathology. The levels of ferrous ion （Fe²⁺）， malondialdehyde （MDA）， 4-hydroxynonenal （4-HNE） and free fatty acid （FFA） in skin tissue were detected. The level of reactive oxygen species （ROS） in skin tissue was detected by immunofluorescence. Immunohistochemistry was used to detect the expression of ChaC glutathione-specific γ-glutamyl transferase 1 （CHAC1）， arachidonic acid 12-lipoxygenase β （ALOX12B）， trimotif protein 21 （TRIM21）， proliferation marker （Ki67） and nuclear transcription factor-κB （NF-κB） protein. ResultsAnalysis of GSE30999 identified 2 100 DEGs and 24 FRGs. Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment revealed 1 000 biological functions and 75 pathways. After cluster analysis， combined with three machine learning algorithms， Nomogram and ROC curve analysis， the core Hub-FRGs （CHAC1， ALOX12 B， TRIM21） were obtained. Immunoinfiltration showed inactive memory CD4⁺T cells and activated dendritic cells abundance significantly correlated with Hub-FRGs. In vivo， model group vs. control showed significantly increased PASI/Baker scores （P<0.05）， epidermal hyperkeratosis， inflammatory infiltration， and elevated levels of Fe²⁺， MDA， 4-HNE， FFA， ROS， CHAC1， ALOX12B， TRIM21， Ki67， and NF-κB （P<0.05）. Drug groups vs. model group exhibited significantly reduced scores （P<0.05）， alleviated skin lesions， and decreased levels of Fe²⁺， MDA， 4-HNE， FFA， ROS， Hub-FRGs， Ki67， and NF-κB （P<0.05）. ConclusionKaixuan Jiedu core prescription can significantly improve the skin pathological injury of psoriasis mice， showing good therapeutic and repair effects， and its mechanism may be related to regulating the expression of ferroptosis genes CHAC1， ALOX12B and TRIM21， which are closely related to the pathogenesis of psoriasis.

ObjectiveTo investigate the efficacy and safety of Kaixuan Jiedu compatibility and the decomposed prescriptions in the treatment of psoriasis. MethodsThirty Balb/c mice were randomly grouped as follows （n=6）： normal， model， Kaixuan Jiedu （KXJD， 15.21 g·kg^-1）， Kaixuan （KX， 3.08 g·kg^-1）， and Jiedu （JD， 12.13 g·kg^-1）. Except the normal group， the rest groups were modeled for psoriasis-like skin lesions by topical application of imiquimod， and samples were collected after 7 days of continuous intervention. Mice were photographed at the lesion site during modeling and before sampling and the psoriasis area and severity index （PASI） was calculated. Hematoxylin-eosin （HE） staining was used to observe pathological changes in the lesions and measure the epidermal thickness. Mice were photographed and observed for the tortuous dilation of dermal capillaries. The expression of vascular endothelial growth factor （VEGF）， platelet-endothelial cell adhesion molecule （CD31）， proliferating cell nuclear antigen （Ki67）， and cytokeratin 10 （CK10） in the epidermal tissue was detected by immunohistochemistry. Immunofluorescence assay was employed to determine the expression of Claudin-1 and Occludin. Real-time PCR was employed to determine the mRNA levels of interleukin-17A （IL-17A） and interleukin-23 （IL-23）. The spleen and thymus were photographed and weighed， and the spleen and thymus indices were calculated. The safety of the treatment was assessed by automatic biochemistry testing of the serum， liver， and kidney functions and by HE staining of the liver， kidney and spleen. ResultsCompared with that of the normal group， the skin of the model group showed erythema， infiltration， and typical psoriasis-like changes， tortuous dilation of dermal capillaries， hyperkeratosis in epidermal cells， acanthosis， massive lymphocytic infiltration in the dermis， impaired barrier function， increased expression of VEGF， CD31， Ki67， and CK10 （P<0.01）， reduced expression of Claudin-1 and Occludin （P<0.01） in the epidermis， and up-regulated mRNA levels of IL-17A and IL-23 （P<0.01）. In addition， the mice in the model group showed spleen enlargement， thymus atrophy， increased spleen index， and decreased thymus index （P<0.01）. Compared with the model group， KXJD and JD reduced psoriasis-like skin lesions， inhibited the tortuous dilation of dermal capillaries， reduced the expression of VEGF， CD31， Ki67， and CK10 （P<0.01）， increased the expression of claudin-1 （P<0.01）， and down-regulated the mRNA levels of inflammatory factors （P<0.01）. Moreover， the KXJD group outperformed the JD group. The JD group showed no significant difference from the model group regarding the spleen index， thymus index， and Occludin expression. The psoriasis indicators in the KX group were not significantly different from those in the model group. ConclusionKXJD and JD can reduce the symptoms of local skin lesions of psoriasis， which is manifested as different inhibition degrees of the proliferation and differentiation of keratin-forming cells， tortuous dilation of dermal capillaries， and inflammatory reactions， as well as the protection of the skin barrier. Moreover， KXJD outperformed JD. KX alone did not significantly reduce psoriasis lesions in mice. KXJD and the decomposed prescriptions are safe and effective， causing no obvious liver and kidney injuries.

Psoriasis is a chronic inflammatory skin disease with a polygenic genetic background. Its etiology remains unclear， and its pathogenesis is complex and refractory， collectively posing significant challenges in its treatment and greatly affecting the physical and mental health of patients. With the advantages of multi-target and multi-pathway treatment， traditional Chinese medicine has shown unique efficacy and value in the diagnosis and treatment of psoriasis. Modern doctors have a lot of discussion on psoriasis， and most of them tend to treat the disease by solving disorders of the blood system. They think that the disease is closely related to the "heat in the blood". Combining the clinical characteristics and accompanying symptoms of psoriasis， this article traced the causes of "heat in the blood" in psoriasis and believed that multiple internal and external factors have prevented the smooth circulation of Qi. Yang Qi Fuyu （stagnation） and transformation into heat and toxicity is the source of "heat in the blood" in psoriasis. Furthermore， it was proposed that "Fuyu" is the core pathogenesis of psoriasis. The etiology of "Fuyu" is complex， such as external wind and cold pathogens， emotional injuries， internal accumulation of dampness， and deficiency of healthy Qi， all of which can disrupt the ascending and descending movement of Qi， impede the circulation of Qi and fluids， close the pores and skin texture， and subsequently lead to stagnation. Based on the above understanding， "resolving stagnation" is crucial for treating the disease. Many doctors have explored the treatment ideas of psoriasis from the perspectives of dispelling wind， warming cold， regulating Qi， eliminating dampness， tonifying deficiency， and external treatment， aiming to remove the causes， promote the circulation of Qi and fluids， and resolve stagnation and heat. Clinical studies have shown that the therapies can relieve clinical symptoms， reduce recurrence rate， and improve quality of life， which also have good safety in the treatment of psoriasis. This article discussed the treatment of psoriasis from the perspective of "Fuyu"， enriching the understanding of TCM regarding the etiology and pathogenesis of psoriasis. It is aiming to serve as an effective supplement to the "treating by solving disorders of the blood system" approach and provide a reference for clinical diagnosis and treatment of psoriasis.

ObjectiveTo explore the effects of Kaixuan Jiedu core prescription （KXJD） on sphingolipid metabolism in the mouse model of imiquimod-induced psoriasis-like skin lesions. MethodsThirty-seven male C57BL/6J mice were randomly assigned into five groups： healthy control （n=11）， model （n=11）， methotrexate （MTX， n=5）， low-dose （15.21 g·kg^-1） KXJD （n=5）， and high-dose （30.42 g·kg^-1） KXJD （n=5）. Psoriasis-like skin lesions were induced in mice with 62.5 mg 5% imiquimod cream applied on the back. The KXJD groups and MTX group were treated with 0.2 mL corresponding decoction and MTX， respectively， by gavage daily， while the other groups were given an equal volume of normal saline by the same way. After 5 days of treatment， back skin lesions were collected. Firstly， healthy control and model mice were selected for tandem mass tag （TMT） quantitative proteomics （control vs model=3 vs 3） and targeted lipid metabolomics （control vs model=11 vs 11）. Then， the binding degree between core components and target proteins was predicted via network pharmacology and molecular docking. Finally， an animal experiment was performed to decipher the specific regulation mechanism of KXJD on sphingolipid metabolism. Immunohistochemistry was employed to determine the expression level of sphingosine-1-phosphate （S1P）， and Western blot was employed to determine the expression levels of sphingosine kinase 2 （SPHK2） and monocyte chemotactic protein-1 （MCP-1）. ResultsTMT proteomics and targeted lipid metabolomics suggested that sphingolipid metabolism was active in the psoriatic skin， and key proteases ［serine palmitoyltransferase， long chain base subunit 2 （SPTLC2）， SPHK2， delta（4）-desaturase sphingolipid 1 （Degs1）， and ceramide synthase 4 （CerS4）］ and 8 sphingolipid metabolites （including ceramides， sphingol， sphingomyelin， and glycosphingolipid） expressed abnormally （P<0.05） compared with those in the healthy skin. The molecular docking results indicated that the binding energy between the active components （quercetin， kaempferol， and luteolin） in KXJD and key proteins involved in sphingolipid metabolism was less than-8 kal·mol^-1. Further experimental verification showed elevated expression levels of SPHK2， S1P， and MCP-1 in psoriatic skin compared with healthy skin （P<0.05）， and KXJD down-regulated the expression levels of SPHK2， S1P， and MCP-1 compared with the model group （P<0.05）. ConclusionThis study indicates that there is an imbalance in sphingolipid metabolism in psoriatic skin lesions. KXJD may reduce psoriasis-like lesions in mice by regulating sphingolipid metabolism via the SPHK2/S1P/MCP-1 pathway.

ObjectiveTo use bioinformatics technology to screen the molecular patterns and diagnostic biomarkers of ferroptosis closely related to psoriasis， observe the therapeutic effect of Kaixuan Jiedu core prescription on psoriasis and explore its potential mechanism through animal experiments. MethodsPsoriasis microarray data from GEO were analyzed to identify differentially expressed genes （DEGs）. Intersection with a ferroptosis gene set yielded psoriasis ferroptosis-related genes （FRGs）， which underwent correlation， consensus clustering， enrichment， and immune infiltration analyses. Core diagnostic FRGs （Hub-FRGs） were identified using random forest （RF）， support vector machine （SVM）， LASSO regression， Nomogram， and ROC analyses. In vivo， imiquimod （5% cream） induced psoriasis in mice （except controls）. Drug treatment groups received respective doses， while control and model groups received saline via daily gavage for 7 days. Back skin changes were recorded and PASI scored. Hematoxylin-eosin （HE） staining assessed histopathology. The levels of ferrous ion （Fe²⁺）， malondialdehyde （MDA）， 4-hydroxynonenal （4-HNE） and free fatty acid （FFA） in skin tissue were detected. The level of reactive oxygen species （ROS） in skin tissue was detected by immunofluorescence. Immunohistochemistry was used to detect the expression of ChaC glutathione-specific γ-glutamyl transferase 1 （CHAC1）， arachidonic acid 12-lipoxygenase β （ALOX12B）， trimotif protein 21 （TRIM21）， proliferation marker （Ki67） and nuclear transcription factor-κB （NF-κB） protein. ResultsAnalysis of GSE30999 identified 2 100 DEGs and 24 FRGs. Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment revealed 1 000 biological functions and 75 pathways. After cluster analysis， combined with three machine learning algorithms， Nomogram and ROC curve analysis， the core Hub-FRGs （CHAC1， ALOX12 B， TRIM21） were obtained. Immunoinfiltration showed inactive memory CD4⁺T cells and activated dendritic cells abundance significantly correlated with Hub-FRGs. In vivo， model group vs. control showed significantly increased PASI/Baker scores （P<0.05）， epidermal hyperkeratosis， inflammatory infiltration， and elevated levels of Fe²⁺， MDA， 4-HNE， FFA， ROS， CHAC1， ALOX12B， TRIM21， Ki67， and NF-κB （P<0.05）. Drug groups vs. model group exhibited significantly reduced scores （P<0.05）， alleviated skin lesions， and decreased levels of Fe²⁺， MDA， 4-HNE， FFA， ROS， Hub-FRGs， Ki67， and NF-κB （P<0.05）. ConclusionKaixuan Jiedu core prescription can significantly improve the skin pathological injury of psoriasis mice， showing good therapeutic and repair effects， and its mechanism may be related to regulating the expression of ferroptosis genes CHAC1， ALOX12B and TRIM21， which are closely related to the pathogenesis of psoriasis.

ObjectiveTo investigate the efficacy and safety of Kaixuan Jiedu compatibility and the decomposed prescriptions in the treatment of psoriasis. MethodsThirty Balb/c mice were randomly grouped as follows （n=6）： normal， model， Kaixuan Jiedu （KXJD， 15.21 g·kg^-1）， Kaixuan （KX， 3.08 g·kg^-1）， and Jiedu （JD， 12.13 g·kg^-1）. Except the normal group， the rest groups were modeled for psoriasis-like skin lesions by topical application of imiquimod， and samples were collected after 7 days of continuous intervention. Mice were photographed at the lesion site during modeling and before sampling and the psoriasis area and severity index （PASI） was calculated. Hematoxylin-eosin （HE） staining was used to observe pathological changes in the lesions and measure the epidermal thickness. Mice were photographed and observed for the tortuous dilation of dermal capillaries. The expression of vascular endothelial growth factor （VEGF）， platelet-endothelial cell adhesion molecule （CD31）， proliferating cell nuclear antigen （Ki67）， and cytokeratin 10 （CK10） in the epidermal tissue was detected by immunohistochemistry. Immunofluorescence assay was employed to determine the expression of Claudin-1 and Occludin. Real-time PCR was employed to determine the mRNA levels of interleukin-17A （IL-17A） and interleukin-23 （IL-23）. The spleen and thymus were photographed and weighed， and the spleen and thymus indices were calculated. The safety of the treatment was assessed by automatic biochemistry testing of the serum， liver， and kidney functions and by HE staining of the liver， kidney and spleen. ResultsCompared with that of the normal group， the skin of the model group showed erythema， infiltration， and typical psoriasis-like changes， tortuous dilation of dermal capillaries， hyperkeratosis in epidermal cells， acanthosis， massive lymphocytic infiltration in the dermis， impaired barrier function， increased expression of VEGF， CD31， Ki67， and CK10 （P<0.01）， reduced expression of Claudin-1 and Occludin （P<0.01） in the epidermis， and up-regulated mRNA levels of IL-17A and IL-23 （P<0.01）. In addition， the mice in the model group showed spleen enlargement， thymus atrophy， increased spleen index， and decreased thymus index （P<0.01）. Compared with the model group， KXJD and JD reduced psoriasis-like skin lesions， inhibited the tortuous dilation of dermal capillaries， reduced the expression of VEGF， CD31， Ki67， and CK10 （P<0.01）， increased the expression of claudin-1 （P<0.01）， and down-regulated the mRNA levels of inflammatory factors （P<0.01）. Moreover， the KXJD group outperformed the JD group. The JD group showed no significant difference from the model group regarding the spleen index， thymus index， and Occludin expression. The psoriasis indicators in the KX group were not significantly different from those in the model group. ConclusionKXJD and JD can reduce the symptoms of local skin lesions of psoriasis， which is manifested as different inhibition degrees of the proliferation and differentiation of keratin-forming cells， tortuous dilation of dermal capillaries， and inflammatory reactions， as well as the protection of the skin barrier. Moreover， KXJD outperformed JD. KX alone did not significantly reduce psoriasis lesions in mice. KXJD and the decomposed prescriptions are safe and effective， causing no obvious liver and kidney injuries.

ObjectiveTo characterize the evidence distribution and methodological quality of randomized controlled trials （RCTs） on oral Chinese herbal medicine （CHM） for atopic dermatitis （AD） based on evidence mapping. MethodsSeven databases （CNKI， Wanfang Data， VIP， CBM， Cochrane Library， PubMed， and Embase） and the Chinese Clinical Trial Registry were searched for the RCTs in Chinese and English. Evidence distribution was presented graphically and textually， and methodological quality was assessed via the Cochrane Risk of Bias tool （ROB 1.0）. ResultsA total of 168 RCTs were included. The number of annual publications showing an increasing trend， and 72.6% RCTs had sample sizes of 51-100 participants. The studies evaluated 108 distinct CHM interventions categorized as decoctions， granules， Chinese patent medicines， and extracts. Compound Glycyrrhizin was the most frequently used， followed by Xiaofengsan and Chushi Weiling decoction. Among the RCTs， 57.1% had the treatment courses of 4-8 weeks. Outcome measures predominantly focused on clinical response rate， skin lesion severity scores， and adverse events， with less attention to TCM symptom scores， skin barrier function， and relapse rates. The overall risk of bias was generally high. ConclusionWhile CHM for AD is a research hotspot and demonstrates clinical advantages， the related studies have problems such as unclear clinical positioning， poor research standardization and methodological quality， and insufficient prominence of TCM clinical advantages. Large-sample， methodologically rigorous， and high-quality studies are needed to enhance the evidence base for CHM in treating AD.