CD4 and neoplasm: CD4 mRNA levels were also higher in the elevated VISTA gene expression group compared to CD8 (p < 0.0001) (Fig. 5a), suggesting that CD8 and CD4 cells are present within the tumor microenvironment but with limited effector function because of the higher expression level of VISTA. As for T lymphocyte-related cytokines, we assessed the expression of two distinct sets.