Scientists investigated the immune landscape across various types of cancer and ultimately classified them into six immune subtypes (C1–C6), including C1 (wound healing), C2 (IFN-γ dominant), C3 (inflammatory), C4 (lymphocyte deficient), C5 (immunologically silent), and C6 (TGF-β dominant), which were assumed to define the immune response with implications for further exploration of immunotherapy [32]. This evidence concerns the gene IFNG and cancer.