Objective:Host genetic factors are known to contribute to disease susceptibility.They may also be important in defining the pattern of disease presentation and progression,as well as its overall prognosis.However,no consistent HLA class-Ⅰ associations have been established in leukemia by PCR/SSOP in Gansu Chinese Han.Such studies have been reported in other counties,with conflicting results.This is the first PCR-based HLA class-Ⅰ association study in northwestern Chinese Han nationality leukemia.Methods:Compared HLA class-Ⅰ in 43 Chinese leukemia patients and 66 healthy Chinese controls as determined by polymerase chain reaction and sequence-specific olignucletide probe hybridization(PCR/SSO) DNA analysis.The present findings imply that HLA-associated genetic factors influence the risk for the development of leukemia.