Foreword: Chaouat, G.; Factors Regulating Trophoblast Invasion: Cohen, M.; Bischof, P.; Histologic and Functional Aspects of the Endometrium in the Implantatory Phase: Bourgain, C.; Devroey, P.; Soluble HLA-G and Embryo Implantation: Frequently Asked Questions: Le Bouteiller, P.; Tabiasco, J.; Parinaud, J.; Uterine Receptivity and Cytokines: New Concepts, New Applications: Ledee, N. et al.; Role of T Cell Cytokines in Decidua and in Cumulus Oophorus during Pregnancy: Piccinni, M.-P.; The Baboon as a Research Model for the Study of Endometrial Biology, Uterine Receptivity and Embryo Implantation: Nyachieo, A. et al.; Dialogue between Blastocyst hCG and Endometrial LH/hCG Receptor: Which Role in Implantation? Perrier d'Hauterive, S. et al.; Role of Aneuploidy on Embryo Implantation: Farfalli, V.I. et al.; Comparative Implantation and Placentation: Chavatte-Palmer, P.; Guillomot, M.