TGFB1 and neoplasm: In addition, the collagen fibers induced by activation of the TGF-β signaling pathway in fibroblasts in the TME restrict the infiltration of T cells into tumor cells, which in turn inhibits the body’s anti-cancer immune response and is regarded as an immunosuppressive cytokine (Batlle and Massagué, 2019; Zhao et al., 2020a).