KRIT1 and cavernous hemangioma: CCM is caused by the loss‐of‐function mutations of any of three independent genes, known as CCM1, CCM2, and CCM3. We have recently reported that the TGFβ/BMP signaling pathway induces an endothelial‐to‐mesenchymal transition (EndMT) in Ccm‐deficient ECs that, in turn, contributes to the development and progression of cavernomas.