It has also been hypothesized that hCG may be a placental link for
the development of local maternal immunotolerance. For
example, hCG-treated endometrial cells induce an increase in T cell apoptosis (dissolution of T-cells). These results suggest that hCG may be a link in the development of peritrophoblastic immune tolerance and may facilitate the trophoblast invasion which is known to expedite fetal development in the endometrium.