JAK2 and deep vein thrombosis: Meanwhile, the revised IPSET-t (r-IPSET-t) algorithm stratifies patients into four groups: very low risk (VLR, no risk factor), low risk (LR, JAK2 mutation), intermediate risk (IR, ≥ 60 years of age) or high risk of thrombosis (HR, history of thrombosis or ≥ 60 years of age with JAK2 mutation) [2].