However, in the same study, no significant difference was found between the CD4, CD8, and CD4/CD8 percentages of patients according to stage and presence of chemotherapy.15 In our study, the percentages of lymphocyte subtype were examined in the peripheral blood sample of 137 patients with PCa, and the CD4+ T lymphocyte values were found to statistically significantly decrease with the increasing PSA value and pathological stage. This evidence concerns the gene CD8A and posterior cortical atrophy.