IDH2 and myeloproliferative disorder: Given the high prevalence of IDH2 mutations in blast phase MPN [12,18] and the synergistic efficacy of JAK2 and IDH2 inhibitors in IDH2/JAK2 mutated-MPN patient cells [36], a phase 2 clinical trial evaluating ruxolitinib in combination with enasidenib in IDH2-mutated patients with chronic MF (4–9% circulating blasts) and MF in the accelerated or blast phase is currently underway (NCT04281498) [86].