CD4 and neoplasm: Expression of a disintegrin and metalloproteinase 17 (ADAM17), a major sheddase of L-selectin (CD62L), by MDSCs cleaves the ectodomain of L-selectin and consequently reduces L-selectin on the surface of naïve CD4+ and CD8+ T cells, therefore limiting their homing to peripheral lymph nodes and tumor sites (20).