It was stated that CD4 T lymphocyte activity was lower in patients with advanced PCa compared to the healthy control group, and this was statistically significant.14 In another study, in which 50 patients with PCa were evaluated in terms of lymphocyte subgroups, Oluboyo et al15 detected a significant decrease in CD8 and CD4 T lymphocytes in peripheral blood in the PCa group compared to the healthy control group. This evidence concerns the gene CD4 and posterior cortical atrophy.