JAM3 and Hydrocephalus: Thus, endothelial re-expression of JAM-C failed to rescue the hydrocephalus phenotype of JAM-C−/− C57BL/6 mice demonstrating that lack of JAM-C in the cerebrovascular endothelium is not the major cause of the development of a hydrocephalus in JAM-C−/− C57BL/6 mice.