Next Generation Sequencing (NGS) showed persistent CALR and DNMT3A mutations, but with lower VAF (2.3% and 1.3%, respectively), while two pathogenic mutations on NRAS and SETBP1 genes were observed (VAF 31% and 33%, respectively), suggesting that the leukaemic transformation evolved at the expense of a different clone than the one associated with the myeloproliferative neoplasm (MPN). This evidence concerns the gene CALR and myeloproliferative neoplasm.