To investigate whether Treg is the cell repository that generates TGF‐β1 in the HCC immune microenvironment, we co‐cultured different treatments of Hepa1‐6 cells with Tregs isolated from tumors of syngeneic orthotopic mice bearing Hepa1‐6‐SOX12 cells (Figure S12F, Supporting Information). The gene discussed is TGFB1; the disease is hepatocellular carcinoma.