TGFB1 and neoplasm: TGF-β-activated Rho GTPases such as RHOA, RAC1, and CDC42 can also contribute to p38 and JNK activation.204,212–216 Both the two MAPKs regulate a series of biological events to respond to all kinds of environmental and intracellular stresses, meanwhile, they engage actively in embryonic development, metabolic regulation, neuronal functions, immunological actions, as well as tumor development.217–220