ASXL1, SRSF2, IDH2 were classified by Tefferi et al. as adverse variants/mutations, in terms of overall- (median survival 7.7 versus 16.9 years), leukemia-free- or myelofibrosis-free survival, with a combined prevalence of 15% (Tefferi et al. 2016). Here, IDH2 is linked to leukemia.