RBPJ and famililal cerebral cavernous malformations: The profound impact of pericyte-specific gene deletion on adjacent endothelial cells within the vascular niche is also evident from an experiment in which the deletion of RBPj, a key transcriptional effector of Notch, within pericytes led to severe hypertrophy and degenerative changes in ECs, eventually resulting in the formation of cerebral cavernous malformation (CCM)-like lesions in the brain (Dieguez-Hurtado et al, 2019).