Although the causal relationship between CMs and DVA has not been fully clarified, a recent genetic analysis of DVAs accompanying CCM lesions with both PIK3CA and MAP3K3 mutations revealed that DVAs have only PIK3CA mutations, indicating that the CCMs developed from DVAs that originally carried the PIK3CA mutation and subsequently acquired MAP3K3 I441M [29]. The gene discussed is MAP3K3; the disease is cerebrocostomandibular syndrome.