NCIt definition : A family of transcription factors that are activated by signaling mediated by tumor
growth factor-beta (TGF-beta) superfamily ligand-receptor interactions. Once activated,
R-SMADs play a role in the positive regulation of TGF-beta responsive gene expression.;
NCIt note : The R-SMAD family includes SMAD1, SMAD2, SMAD3, SMAD5, and SMAD8.;