Could play a role in the determination of the epiblastic cells that subsequently give rise to the mesoderm. Activates the Nodal-dependent signaling pathway. Expressed weakly in lung, colon and breast. Expressed also strongly in primary cancer tissues; lung and colon cancers. Belongs to the EGF-CFC (Cripto-1/FRL1/Cryptic) family. Could be the product of a pseudogene. The TDGF3 locus has characteristics of a retrotransposon, including lack of introns and a poly(A) sequence.