To exclude a cell-type-specific effect of the striking cancer-like proliferation of CCM3−/− CI-huVECs in co-culture, we differentiated hiPSCs into human brain microvascular endothelial-like cells (hBMEC-like cells; Fig. 4a, Online Resource 6) and co-cultured CCM3−/− and CCM3+/+ hBMEC-like cells in a 1:9 ratio. This evidence concerns the gene PDCD10 and cancer.