Specifically, the absolute numbers of CD3+, CD4+, and CD8+ T cells significantly increased in the peripheral blood of R/R and naïve CLL patients before ibrutinib treatment (22, 28, 34, 44, 45), particularly CD8+ T cells (20, 44), which resulted in a decreased CD4:CD8 ratio (28, 45) (Figure 2A). The gene discussed is CD4; the disease is B-cell chronic lymphocytic leukemia.