CD274 and hepatocellular carcinoma: Using single cell RNA sequencing data, our laboratory recently showed that PD-L1 expression is mainly found in the myeloid population rather than tumor cells in human hepatocellular carcinoma and intraductal cholangiocarcinoma samples and that the expression of PD-L1 on TAMs is highly dependent on intact hedgehog signaling cascade in these macrophages [27].