In this study, the frequency of T-lymphocytes and their subsets in the schistosomal BCa group showed reduction in the level of total lymphocytes (CD3+), T helper (CD4+) cells, and cytotoxic T (CD8+) cells in tumor tissues compared to controls (group B) that was statistically significant (p < 0.001) (Table 5). This evidence concerns the gene CD4 and neoplasm.