ANGPT1 and hereditary hemorrhagic telangiectasia: Suggestively, human sporadic bAVM samples, similar to these lesions in the inherited syndrome HHT, also feature decreased TIE2 protein levels [216], as well as diminished levels of the TIE2 agonist ANGPT1, but increased transcript and protein levels of the TIE2 antagonist ANGPT2 [217]; trends which were generally confirmed in a recent scRNA-seq study of human sporadic bAVM samples [218].