TAP2 and cancer: Notably, most of the IL-4 mRNA production in human NSCLCs is in CD11b-expressing intratumor myeloid cells supporting a multicellular mechanism involving IL-4 production by alternatively polarized TAMs/MDSCs signaling in an autocrine fashion to induce and/or maintain an immune suppressive state of these cells; and paracrine IL-4 signaling on cancer cells reducing TAP2 expression and favoring tumor immune evasion.