KRIT1 and cerebral cavernous malformation: MGC4607/CCM2 loss accounts for up to 38% of familial CCM cases.[23, 30] This gene is located on chromosome 7p13-15.[13] MGC4607/CCM2 has a similar temporal and spatial expression pattern as Krit1/CCM1 within the endothelium of the arteries.[48] Just like Krit1/CCM1, MGC4607/CCM2 is also expressed in astrocytic foot process and pyramidal neurons, suggesting a putative role in blood-brain barrier formation.