IFNG and neoplasm: In concert with the importance of CD8 T cell-mediated tumor recognition and killing for tumor control, tumor expression of antigen-presenting major histocompatibility class I (MHC-I) molecules [10] and intact IFNγ signaling [11,12] correlate with immunotherapy response, while a deficiency in MHC-I expression [13,14] or IFNγ response [11,12], are associated with immunotherapy resistance.