Immunohistochemical staining showed that PDL1 levels were higher in the lung metastasis group of HCC patients than in HCC patients without extrahepatic metastasis, and MUC1 was positively correlated with PDL1 (r = 0.4077, P = 0.0002) (Fig. 5c-e). This evidence concerns the gene MUC1 and hepatocellular carcinoma.