KRAS and neoplasm: It is well established that KRAS mutants contribute to the immunosuppressive tumor microenvironment through multiple mechanisms,493–496 including prompting M1 to M2 polarization of macrophages, inducing regulatory T cell differentiation by secreting TGF-β and IL-10, enhancing infiltration of myeloid-derived suppressor cells, and disrupting CD8+ cytotoxic T cells activation through modulation of immune checkpoint signaling.