HLA-DRB1 and acute lymphoblastic leukemia: In Chinese population, our previous results indicated that as compared with the control, the frequency of HLA-DRB1*09 in ALL group significantly decreased (10.87% versus 16.08%, P = 0.014), while the frequency of HLA-B*18 in CML group was significantly higher (1.28% versus 0.20%, P = 0.039) [3].