In order to determine if the lack of endothelial JAM-C expression in the brain of C57BL/6 mice caused the development of the hydrocephalus, we bred JAM-C+/−//Tie2-JAM-C mice with JAM-C+/− mice and compared the occurrence of the hydrocephalus and the survival of JAM-C−/− versus JAM-C−/−//Tie2 JAM-C offspring. The gene discussed is JAM3; the disease is Hydrocephalus.