JAK2 and essential thrombocythemia: In 2012, on the basis of these pieces of evidence, the International Prognostic Scoring of Thrombosis in ET (IPSET-thrombosis) was developed by adding the JAK2 mutated status and cardiovascular risk factors (2 and 1 points, respectively) to the classic variables older age (>60 years) and prior thrombosis (1 point each) [91].