FNDC5 and hepatocellular carcinoma: The human adult cardiomyocyte AC16 and the human hepatocellular carcinoma cell lines including HepG2, Sk-Hep1 and SNU449 showed high mRNA expression level of FNDC5 variants which were observed in normal heart and liver tissues, while Huh7 cells exhibited extremely low levels of the three FNDC5 variants.