Cancer cells express tumor-specific neoantigens that arise from an inefficient DNA damage repair system and which are presented to the CTLs by the human leukocyte antigen (HLA) system class I. Then, tumor cells are killed through a combination of direct perforin-dependent destruction and by increasing tumor immune sensitivity through the release of inflammatory cytokines, such as interferon (IFN) alpha (INF-α) and tumor necrosis factor (TNF) (30, 34, 35). This evidence concerns the gene PRF1 and neoplasm.