Mutations in the CCM3/PDCD10 gene (CCM3 from here on) predispose to cerebral cavernous malformations (CCM, OMIM #116860), a common type of vascular malformation which develop almost exclusively in the central nervous system (Rigamonti et al., 1988). The gene discussed is PDCD10; the disease is famililal cerebral cavernous malformations.