N-glycans of human amniotic fluid transferrin stimulate progesterone production in human first trimester trophoblast cells in vitro - Jeschke,U.; Gundel,G.; Muller,H.; Richter,D.U.; Streu,A.; Briese,V.; Mylonas,I.; Friese,K.; Unverzagt,C. (J Perinat Med, 2004)