SIRT4 and colorectal carcinoma: In addition, SIRT4 overexpression significantly reduced the rates of the S phase and G2/M phases of two CRC cell lines after 5-fluorouracil treatment, but had no effect on the apoptosis rate, indicating that SIRT4 increased the sensitivity of CRC cells to 5-fluorouracil by delaying mitosis (81) (Figure 5).