SIRT3 and colorectal carcinoma: For example, overexpression of SIRT3 improves anticancer drug resistance of CRC cells through superoxide dismutase (SOD) 2 and PGC-1α regulation.451 In addition, SIRT4 increases the sensitivity of CRC cells to chemotherapeutic drug 5-fluorouracil by inhibiting the cell cycle.447 Regarding radioresistance of CRC, FoxQ1-mediated SIRT1 upregulation augments expression and nuclear translocation of β-catenin and benefits CRC-related intestinal pathological bacteria, thereby enhancing the radioresistance of CRC cells.452