Similar to patients with MDS, Rpl22−/− mice displayed a significant reduction in red blood cells (RBCs) with increased mean corpuscular volume (MCV), as is observed in macrocytic anemia associated with MDS (Figures 2A and 2B).29 Rpl22-deficient mice also exhibited evidence of erythroid and myeloid dysplasia (Figures S1B and S1C) and an increased frequency of megakaryocytes (Figure 2C). Here, RPL22 is linked to myelodysplastic syndrome.