SIRT5 and hepatocellular carcinoma: We first detected the expression of SIRT4, along with other mitochondrial Sirtuins including SIRT3 and SIRT5, in the paired Hep-11 and Hep-12 HCC cell lines, which originated from the same patient's primary and recurrent HCC tissues and represented non-tumorigenic and TIC-enriched cell populations, respectively 28.