SIRT4 and breast cancer: In an investigation of the precise roles of sirtuin genes, high‐throughput real‐time PCR analysis showed that SIRT4 expression was significantly lower in breast cancer tissues than in adjacent breast tissues.24 Another study showed that C‐terminal‐binding protein promotes growth and represses apoptosis in the breast cancer cell lines MCF‐7 and MDA‐MB‐231 by downregulating SIRT4.25, 26 These findings indicate that SIRT4 acts as a tumor suppressor gene, inhibiting cell growth and promoting apoptosis in breast cancer.