The diagnostic criteria are based on the presence of major molecular hematopoietic drivers: the most frequent are the V617F mutation in the JAK2 gene, mutations in exon 10 of the MPL gene (mainly involving codon W515), which are present in 90% of patients with PV, and JAK2 mutations in exon 12 [5]. This evidence concerns the gene MPL and acquired polycythemia vera.