One example is the 5T4 oncofoetal antigen originally defined by a monoclonal antibody raised against human trophoblast.
This interface, consisting of the maternal decidua and the invading placental trophoblast, is exposed to profound changes in oxygen tension during pregnancy.
Molar disease expressed P2Y6 in the villous trophoblast but not in the proliferative intermediate trophoblast, recapitulating the pattern of first-trimester placenta.
In this paper we hypothesized that invasive trophoblast released vasodilators which would dilate spiral arteries as an initial step in the physiology of transformation.
Kliman and the team identified trophoblast inclusions by performing microscopic examinations of placental tissues.