CES1 and hepatocellular carcinoma: Intriguingly, even though artificially overexpressed CES1 was shown to exert a antiproliferative function in the liver cancer cell line Hep3B, its protein levels have long been considered undetectable in HCC and HCC-derived cell lines, probably because of the lack of high-affinity antibodies that specifically recognize endogenous CES1 (38–40).