YAP1 and hepatocellular carcinoma: However, a previous study found significant overexpression and activation of YAP-1 in PBMCs collected from a total of 152 hepatocellular carcinoma cases, and showed that YAP-1 shares a positive correlation to the percentage of Treg cells; specifically, YAP-1 overexpression in hepatocellular carcinoma T cells induces immunosuppression by promoting Treg cell differentiation [38].