IFNG and gastrointestinal stromal tumor: IFN‐γ also drives a pro‐inflammatory phenotype in macrophages and enhances the antigen presentation capacities of professional APCs.50 Interestingly, IFN‐γ production by γδ T cells also enhances MHC I molecule expression at the surface of B16 melanoma cells, thereby promoting their recognition by CTLs (Figure 2).51 A recent study in a mouse model of gastrointestinal stromal tumor describes a protective role for γδ T cells mediated through the secretion of GM‐CSF.