CD4 and neoplasm: In gastric cancer, a CD19 + CD24hiCD38hi B reg population that plays immunosuppressive roles by producing IL-10 and TGFβ has been identified; this cell population is inhibiting cytokine production by CD4+ T cells and promotes the conversion of CD4 + CD25- effector T cells to CD4+FoxP3+Treg cells, which collectively promote tumor growth [30].