GPR50 and hepatocellular carcinoma: Moreover, we checked GPR50 mRNA and protein expression levels in the normal hepatocyte cell line MIHA and several HCC cell lines, including HepG2, SNU449, and SNU475, via reverse-transcriptase PCR (RT-PCR) and western blot analyses and found that GPR50 expression was clearly overexpressed in the HCC cell lines (Figure 1F).