Ruxolitinib is a potent, first-in-class inhibitor of JAK1/JAK2 for the treatment of adult patients with PV who have an inadequate response to or are intolerant of HU and has been shown to reduce the occurrence and risk of thrombosis [12,13,14], improve patients’ quality of life, and improve patient-reported outcomes [15]. This evidence concerns the gene JAK2 and acquired polycythemia vera.