CD4 and osteosarcoma: Our data demonstrated that higher infiltrations of activated B cell s, activated CD8 T cells, central memory CD4 T cells, central memory CD8 T cells, regulatory T cells, type 1 T helper cells, CD56bright natural killer cells, macrophages, MDSC, natural killer cells, and natural killer T cells were found in the low-risk osteosarcoma in comparison to the high-risk osteosarcoma in the TARGET cohort (Figure 8A).