TGFB1 and neoplasm: Moreover, we show that Nodal contributes to the conversion of fibroblasts to CAFs in vitro through α-SMA detection compared to normal fibroblasts and those treated with self-derived Nodal protein, exogenous recombinant Nodal protein, or tumor cell-derived Nodal protein in a process that involves Snail and the TGF-β signaling pathway.