Placental Alkaline Phosphatase Antibody / ALPP

Alkaline phosphatase, placental type is a membrane-bound glycosylated dimeric enzyme, also referred to as the heat-stable form, that is expressed primarily in the placenta, although it is closely related to the intestinal form of the enzyme as well as to the placental-like form.

PLAP is a tumor marker, especially in seminoma and ovarian cancer. PLAP is reliable only in non-smokers, as smoking interferes with measurement of PLAP, since serum concentrations of PLAP are increased up to 10-fold in smokers and its measurement is therefore of little value in this group. [Wiki]