fig3

Figure 3. The relationship between cytotoxic T cells and cancer cells in a body resembles the relationship between tumor suppressor APRO family proteins and oncogenesis in a cell. It could be hypothesized that the former is regulated with immune checkpoint molecules such as PD1/PDL1 and CTLA4, whereas the latter may be regulated by various miRNAs. The gut commensal microbiota might support both phases of the anti-cancer activity via unclear factors, possibly including ROS and/or SCFAs. APRO: Anti-proliferative; CTLA4: cytotoxic T-lymphocyte-associated protein 4; PD1: programmed cell death protein 1; PDL1: programmed cell death ligand 1; BTG1: B-cell translocation gene 1; TOB: transducer of ErbB-2; ROS: reactive oxygen species; SCFAs: short-chain fatty acids.