IFNG and gastrointestinal stromal tumor: Imatinib increases the infiltration of NK cells in GIST [99] and augments their ability to secrete IFNγ [95, 113, 134, 175, 192, 193] which was positively correlated with PFS [134, 136] and was an independent predictor of long-term survival of GIST patients with imatinib therapy [136, 175].