The tale of transforming growth factor‐beta (TGFβ) signaling: A soigné enigma

Transforming growth factor‐beta (TGFβ) is a secreted cytokine, which intricately controls a plethora of physiological and pathological processes during development and carcinogenesis. TGFβ exerts antiproliferative effects and functions as a tumor suppressor during early stages of tumorigenesis, whereas at later stages it functions as a tumor promoter aiding in metastatic progression through an autocrine TGFβ loop. Intricate knowledge of TGFβ signaling and its regulation are still evolving. In this review, we make an attempt to showcase the associated enigma of TGFβ signaling in its dual functional role as tumor suppressor and metastatic promoter during early and late stages of carcinogenesis, respectively. © 2009 IUBMB IUBMB Life, 61(10): 929–939, 2009