Currently known MPN‐associated mutations now include JAK2, MPL, LNK, CBL, CALR, TET2, ASXL1, IDH1, IDH2, IKZF1 and EZH2. Enhancing our knowledge about the mutation profile of patients may allow them to be stratified into risk groups which would aid clinical decision making. The gene discussed is MPL; the disease is myeloproliferative disorder.