STAT3 and hepatocellular carcinoma: Over the last decade, the mechanistic connection between STAT3 signaling and PD-L1 expression has been indicated in several cancers including liver cancer, bladder cancer and colorectal cancer.53–55 We also demonstrated the inhibition of STAT3 signaling can significantly downregulate the expression of PD-L1, which required APOJ existence in HCC cells.