Breast cancer can be classiifed into 4 intrinsic subtypes by gene expression proifling: basal-like, HER-2-positive, Luminal A and Luminal B. Although Luminal cancers share similarities, the studies showed that Lu-minal A and B breast cancers should be perceived as distinct entities. Luminal B breast cancer has lower expression of hormone receptors, and it also exhibits worse prognosis and has a distinct proifle of response to chemotherapy and en-docrine therapy. This review presented the available clinical evidence for chemotherapy and endocrine therapy patterns of response, and potential targets for treatment.