To address these questions, another in vitro model of XLSA should be established, such as R452H and R411C, which are other common ALAS2 mutations1,2,5, or R163H and Y365H, which are associated with female patients with macrocytic sideroblastic anemia due to severe ALAS2 loss-of-function mutation16,17. Here, ALAS2 is linked to X-linked sideroblastic anemia 1.