CD4 and B-cell non-Hodgkin lymphoma: Differences in T-cell subtypes and the function of memory and effector T cells were found to be important factors in CAR-T-cell immunotherapy [36]. Both CD8+ and CD4+ subsets play synergistic roles in antitumor activities, and as demonstrated in patients with B-cell non-Hodgkin lymphoma [37] and in a mouse model [38], the high anticancer activity of CAR-T cells was correlated with a ratio of CD4+ to CD8+ T cells of 1:1.