SEC23B and macrocytic anemia: The reduction of SEC23B presents an intriguing explanation for the macrocytic anemia in individual V-8, since biallelic variants in one of the SEC24 binding partners (16), SEC23B, cause congenital dyserythropoietic anemia type II (anemia, congenital dyserythropoietic, type II; CDAN2, OMIM 224100).