CD4 and neoplasm: In contrast to these studies, in our tumor models, which are poorly infiltrated by T cells, and resistant to RT and αPD−1/PD-L1, we observed an increase in Ki−67 expression, suggesting an increase in T-cell proliferation, but no effect on either the proportion of CD4+ or CD8+ T-cells nor on IFN-y production by CD8+ T-cells.