When tumor-reactive T lymphocytes mount an adequate response against tumor neoantigens, IFN-γ is produced in the TME which activates JAK/STAT signaling, which in turn activates the transcription factor interferon regulatory factor 1 (IRF1), culminating in the transcription of cd274 (whose protein product is PD-L1). The gene discussed is IFNG; the disease is neoplasm.