On the other hand, somatic mutations in the endoplasmic reticulum chaperone gene (CALR) are detectable in a majority of myeloproliferative neoplasms (MPN) patients with non-mutated JAK2 and in a small proportion of MPN somatic mutations in the MPL gene have been also reported [18,19]. This evidence concerns the gene CALR and myeloproliferative disorder.