Along these lines, in cancer cells Nrp1 differentially impacts TGFβ versus bone morphogenetic protein (BMP) signaling via Smads, with RNAi-mediated Nrp1 silencing leading to increased levels of pSmad1/5/8 and diminished levels of pSmad3 (Cao et al., 2010). This evidence concerns the gene TGFB1 and cancer.