The prognostic scoring systems for primary myelofibrosis have evolved from phenotype driven (IPSS/DIPSS) to now include information about additional gene mutations (DIPSS-plus and MIPSS, identifying high risk molecular lesions identified as mutations in ASXL1, SRSF2, U2AF1, EZH2, IDH1 and IDH2) [82]. Here, EZH2 is linked to myelofibrosis.