Clinical and Biochemical Data in Cluster 1–5 with low, low-intermediate, intermediate, intermediate-high, and high expression values of the 5 genes, respectively.

Median and range are shown. Abbreviations: ET =  Essential Thrombocythemia; PV =  Polycythemia Vera; PMF =  Primary Myelofibrosis; *  =  blood tests at the time of blood sampling for gene expression profiling; disease duration at the time of blood sampling; **:from diagnosis as assessed January 2013.