Fig. 3.

Activators and signaling components of the TGF-β signaling pathway. A non-exhaustive list of activators of TGF-β signaling (shown in dark brown circles) where one activator may lead to the convergence with the other (green arrows). The downstream signaling receptors and signal transducers (left panel) and important downstream co-operative molecules regulating epithelial-mesenchymal transition (right panel) are listed as side panels. SARA Smad anchor for receptor activation, TAK1 TGF-β activated kinase-1, MAPKs mitogen-activated protein kinases, PRC2 polycomb-repressive complex-2, AP-1 activator protein-1 (Jun/Fos/Fra), EMT-TFs epithelial-to-mesenchymal transition regulatory transcription factors, MCTs monocarboxylate transporters, ECM extracellular matrix, EPO erythropoietin, AJ adherens junction