In patients with CLL, compared to HV, we observe a slight decrease in the frequency of CD45+ leukocytes and a significant decrease in CD3+ T lymphocytes (by 82.98%), as well as a decrease in the percentage of individual subpopulations of CD4+ T lymphocytes (by 87.34%) or CD8+ T lymphocytes (by 84.17%). This evidence concerns the gene CD8A and B-cell chronic lymphocytic leukemia.