PTEN and hepatocellular carcinoma: These observations are supported by a recent study revealing that ER stress is linked to immune cell function, [22] and Liu et al. [23] showing that ER-stressed HCC cells release exosomes to upregulate PD-L1 expression in macrophages, which subsequently inhibits T-cell function through an exosome miR-23a-PTEN-AKT pathway.