Additionally, Endoglin, a transforming growth factor beta superfamily auxiliary receptor, was shown to inhibit prostate cancer motility via activation of the Alk2/Smad1 pathway [37], and BMP7 inhibition of epithelial-to-mesenchymal transition was lost when Alk2 were knocked down in a melanoma cell line [38]. Here, SMAD1 is linked to prostate cancer.