Human STAMP2, also called Steap4 or TIARP (TNF-alpha-induced adipose-related protein), is a 55 kDa, 459 aa, 6-transmembrane (TM) member of the Steap family of metalloreductases. It is induced by androgens in androgen-regulated prostate cells, and is up-regulated during adipocyte differentiation by TNF-alpha. Full-length human and mouse STAMP2 share 80% aa identity. A 283 aa variant lacks a portion of the oxidoreductase domain and three TM domains. STAMP2 is present in the Golgi complex and early endosomes in addition to the cell surface.