There are at least four distinct but related alkaline phosphatases: intestinal, placental, placental-like, and liver/bone/kidney (tissue non-specific). The product of this gene is a membrane bound glycosylated enzyme, localized to testis, thymus and certain germ cell tumors, that is closely related to both the placental and intestinal forms of alkaline phosphatase. [provided by RefSeq, Jul 2008].