The first group included studies that genetically characterized MPN from different aspects, among which the detection of methylations [17] and epigenetic alterations [31], the search of structural rearrangements in JAK2 [33], comparative genomics for the diagnosis [37], the identification of new genetic markers [14], and mutations associated with pathogenesis [60] or mutations in CALR and MPL in negative JAK2 patients [41, 70] all stood out. This evidence concerns the gene CALR and myeloproliferative neoplasm.