Interestingly, the level of PCDH18 gene expression was significantly lower in EpCAM-positive HCC cells (HCC1, HCC2, Huh1, Huh7, HepG2, and Hep3B) compared with EpCAM-negative HCC cells (PLC/PRF/5, HLE, HLF, and SK-Hep-1; P = 0.038; Fig. 4). Here, PCDH18 is linked to hepatocellular carcinoma.