CALR and myeloproliferative disorder: More recently, it has also been shown that HSCs with CALR haploinsufficiency display MPN-like features, including reduced bone marrow erythropoiesis and splenic extramedullary hematopoiesis; the combination of CALRDel52 and CALR haploinsufficiency restores the self-renewal capacity of mutant HSCs, eliminating the competition from wild-type cells and aiding the expansion of mutant clones towards MPN [40].