Primary and adaptive resistance may result from intrinsic mechanisms that fall into one of the following four categories: (1) absence of tumor antigens and deficient T-cell detection (2) defects in antigen presentation and lack of HLA molecules, (3) constitutive expression of immune checkpoint ligands (4) dysregulation of signaling pathways, including MAPK, PI3K, WNT/β-catenin, and IFN-γ [85]. The gene discussed is IFNG; the disease is neoplasm.