ALDH1A1 and hereditary elliptocytosis: Specifically, pre-hemogenic endothelium (HE) and HE in vitro displayed either undetectable or weak expression of ALDH1A1, Wnt, and TGFβ/BMP inhibitors, which were found to be crucial regulators of endothelial-to-hematopoietic transition (EHT) in vivo.