PV clinical and research goals. The 2005 JAK2^V617F discovery opened new windows for the understanding and treatment of PV. Hydroxyurea and phlebotomy have been used in the past and at present to manage cytoses. In 2014, the first targeted therapy, ruxolitinib, was approved for PV. More recently the focus has shifted to understanding disease latency and targeting clonal expansion, and ropeginterferon was approved in 2021.