TMEFF2(transmembrane protein with EGF-like and two follistatin-like domains 2), a gene encoding a plasma membrane protein with two follistatin-like domains and one epidermal growth factor-like domain, had limited normal tissue distribution and was highly overexpressed in prostate cancer. The shedded form up-regulates cancer cell proliferation, probably by promoting ERK1/2 phosphorylation. Down-regulated in tumor cell lines in response to a high level of methylation in the 5' region. Clone J4B6, is derived from hybridization of mouse F0 myeloma cells with spleen cells from BALB/c mice immunized with a recombinant human TMEFF2 protein.