BMP6 and cerebral cavernous malformation: Recently, we extended these observations showing, both in vitro and in vivo, that in the absence of CCM endothelial AJ are dismantled (Lampugnani et al, 2010; Boulday et al, 2011; Maddaluno et al, 2013) and endothelial cells (ECs) lining the cavernomas undergo endothelial‐to‐mesenchymal transition (EndMT) (Maddaluno et al, 2013) induced by a strong activation of the phospho‐SMAD‐dependent signaling pathway due to an increased endogenous production of the BMP6 ligand.