IFNG and neoplasm: Since all APM components can be transcriptionally upregulated by interferon (IFN)-γ, mutations in the components of its signaling pathway such as janus kinases (JAK) or signal transducer and activator of transcription (STAT) [50,61,62] can make tumor cells resistant to immunotherapy by avoiding recovered/enhanced antigen presentation [63] even in response to local IFN-γ production during an ongoing immune response.