Unlike these α5-PKO mice, mutants with laminin-γ1 deficiency (all γ1-containing laminins) in mural cells showed BBB breakdown and hydrocephalus in C57Bl6-FVB mixed background [26], suggesting an important role of mural cell-derived γ1-containing laminins in BBB maintenance and hydrocephalus pathogenesis, although we cannot exclude the possibility that BBB disruption is secondary to hydrocephalus. This evidence concerns the gene LAMB2 and Hydrocephalus.