Several pre-clinical studies have provided evidence on the role of Janus kinase 2 (JAK2) as a potential target to treat disorders with ineffective erythropoiesis.15 The inhibition of JAK2 in TDT and NTDT mouse models improved ineffective erythropoiesis and reversed splenomegaly.16 A phase 2a study (NCT02049450) assessed ruxolitinib efficacy and safety in TDT patients with spleen enlargement. This evidence concerns the gene JAK2 and Splenomegaly.