However, there was a trend towards a higher incidence of thrombotic events (33% vs. 22%) and especially disease progression – i.e. transformation to AML or post-PV fibrotic progression (33% vs. 13%) in JAK2-R1063H-positive group (Fig. 6A right, Supplemental Table 2A). This evidence concerns the gene JAK2 and acute myeloid leukemia.