TGFB1 and cancer: In another study, Tauriello and colleagues revealed a highly active TGFB signaling in colorectal tumor stroma and identified cancer-associated fibroblast cells as the main source of TGFB.8 Consistently, the combined administration of an anti-PD-L1 antibody and the TGFB type I receptor-specific inhibitor galunisertib in a metastatic mouse model induces lymphocyte infiltration in the tumor microenvironment and enhances the production of granzyme B+ and interferon γ+ effector T cells, eventually leading to metastatic tumor cell death and consequent survival of the mouse without any recurrence.