DLL1 and hereditary elliptocytosis: When NOTCH signaling was manipulated, either by the addition of Resveratrol during mesodermal specification [162], by a 4-day incubation of human PSC-derived immature HE progenitors on immobilized NOTCH ligand DLL1 [163], or by culture under hypoxic conditions [185], arterial-type HE also emerged in culture.