TGFB1 and hepatocellular carcinoma: To further understand how Tregs contribute to induce CCL5 expression in HCC cells, the five most-established Treg-derived cytokines, including TGF-β1, IL-10, IL-35, VEGF, and TNF-α were examined in culture medium from Huh7 cells cocultured with or without Tregs, using cytometric bead array (CBA).