STAT1 and neoplasm: Transcription factors such as signal transducer and activator of transcription 1 (STAT1), interferon Regulatory Factor 1 (IRF-1), nuclear factor kappa B (NF-κB), and hypoxia-inducible Factor 1α (HIF-1α) directly control the expression of antigen-processing machinery (APM) components, including TAP (14, 15), Endoplasmic reticulum aminopeptidase (ERAP) (16–18), and MHC-I molecules, thereby determining the basal readiness of tumor cells for immune recognition.