TGFB1 and neoplasm: On the other hand, B cells have been shown to mediate tumor growth, as regulatory B cells express inhibitory molecules such as programmed cell death-ligand 1 (PD-L1) and FAS ligands, as well as anti-inflammatory mediators such as TGF-β, IL-10, and IL-35, resulting in the suppression of immune responses leading to cancer cell immune escape (16).