Implantation of the fertilized ovum in the lining of the uterus requires a complex orchestration of cellular changes within the mother and when these go wrong, the success of reproduction is at risk. A variety of diseases can affect the reproduction, including when the mother's immune system reacts against the embryo. Researchers are therefore studying the cellular changes that occur upon fertilization, and determining the role of immunity in reproduction. Another function critical for normal pregnancy is the ability of new fine blood vessels to proliferate and so cope with the nutritional needs of the growing embryo. On the male side, researchers in the Department are also studying the various causes of male infertility.