Liu et al. [67] found that HCC cell-derived exosomes produced by endoplasmic reticulum stress that contain high levels of microRNA (miRNA/miR)-23a-3p could increase the expression of PD-L1 on macrophages through the PTEN/AKT pathway, resulting in the suppressed immune functions of T cells. Here, CD274 is linked to hepatocellular carcinoma.