Schistosome parasites lay up to a thousand eggs per day inside the veins of their mammalian hosts. The immature eggs deposited by females against endothelia of venules will embryonate within days. Approximately 30% of the eggs will migrate to the lumen of the intestine to continue the parasite life cycle. Many eggs, however, are trapped in the liver and intestine causing the main pathology associated with schistosomiasis mansoni and japonica, the liver granulomatous response. Excretory/Secretory egg proteins drive much of egg-induced pathogenesis of schistosomiasis mansoni, and Schistosoma japonicum induce a markedly distinct granulomatous response to that of S. mansoni.