SF3B1 and Increased total leukocyte count: Conventional survival assessment in ET is based on the International Prognostic Score for ET (IPSET‐survival) which includes age > 60 years, leukocytosis > 11 × 109/L, and prior thrombosis [7], with recent incorporation of spliceosome (SRSF2/SF3B1) mutations, age > 60 years and male gender, in the mutation-enhanced international prognostic scoring system (MIPSS-ET) [8].