TGFB1 and neoplasm: In advanced solid tumors, TGFβ overexpression can reduce chemotherapy efficacy by (1) excessive ECM deposition (collagen, hyaluronan, fibrin), which creates a dense physical barrier hampering the penetration of chemotherapeutic drugs into the tumor; (2) aberrant blood vasculature interfering with drug delivery; (3) EMT, which is accelerated by chemotherapeutic agents, leading to carcinoma cell dissemination and drug resistance; and (4) cancer stem-like cells (CSCs, or tumor initiating cells; TICs) resistant to chemotherapeutic drugs causing tumor relapse 31.