PMEPA1 encodes a transmembrane protein that contains a Smad interacting motif (SIM). Expression of PMEPA1 is induced by androgens and transforming growth factor beta, and the encoded protein suppresses the androgen receptor and transforming growth factor beta signaling pathways though interactions with Smad proteins. Overexpression of PMEPA1 may play a role in multiple types of cancer. Alternatively spliced transcript variants encoding multiple isoforms have been observed for PMEPA1.