NPM1 and myeloproliferative disorder: Conversely, in 6 patients, NPM1 mutations were not found during the antecedent MDS phase [38,39], as also reported by Courville et al. [40], therefore suggesting, before the identification of dynamics of hematopoietic clones characterized by next generation sequencing (NGS) assays, that this molecular lesion could also be acquired during the transformation process as a secondary event, at least in rare cases of sAML arising from MDS or MDS/MPN [38,39,40].