To mimic the mosaic endothelial pattern in CCM tissue, in which the number of mutant ECs is usually much lower than the number of wild-type cells [15–18], we co-cultured CCM3−/− with CCM3+/+ CI-huVECs in a 1:9 ratio for six days (Fig. 2a). The gene discussed is PDCD10; the disease is cerebral cavernous malformation.