Furthermore, there is emerging evidence that the myeloid-derived suppressor cells (MDSCs), recruited to the tumor microenvironment through CXCR2 signaling, play a crucial role in protecting tumors from the cytotoxic T cell–mediated antitumor effect and in suppressing the efficacy of immune checkpoint blockade (ICB) (Talmadge, 2007; Gabrilovich et al., 2012). This evidence concerns the gene CXCR2 and neoplasm.