Second, various components of immune system such as interferon-γ (IFN-γ), IFN-γ receptor, transcription factor signal transducers and activators of transcription 1 (STAT1), perforin, and interleukins which can affect in situ immune reaction against tumour, and therefore, impact on patients' survival were not considered. The gene discussed is IFNG; the disease is neoplasm.