TGFB1 and hepatocellular carcinoma: On the other hand, the increase in MO-MDSC in Pt.3 was consistent with previous reports showing an increase, both in blood and in tumor tissue of HCC patients, of a population of MDSC with immunosuppressive activity through the induction of Tregs [46] and the regulation of hepatic NK-cell activity via TGF-β [47].