Loss of SEC23B has been demonstrated to be lethal in mice because of pancreatic insufficiency and hypoglycaemia.[23] Biallelic mutations in the SEC23B gene (20p11.23) cause type II congenital dyserythropoietic anemia (CDAII) due to aberrant assembly or deconstruction of the midbody during cytokinesis and erythroid differentiation disorder.[24, 25] Post‐translational modification plays a key role in the regulation of SEC23B. Here, SEC23B is linked to congenital dyserythropoietic anemia type 2.