HLA-A, HLA-B 2-mismatch were risk factors of prostate cancer after KT, while HLA-DR both 1-mismatch and 2-mismatch were risk factors of prostate cancer after KT, which can be explained as follows: Firstly, HLA-A, HLA-B 2-mismatch increased the risk of prostate cancer after transplantation, while 1-mismatch results were not statistically significant, indicating that an increase in mismatches in HLA-A and HLA-B could add to the risk of prostate cancer after transplantation. The gene discussed is HLA-B; the disease is prostate cancer.