JAK2 and myeloproliferative disorder: The JAK2 V617F mutation is the most commonly acquired driver mutation of the myeloproliferative neoplasms (MPN), detected in more than 95 % of patients with polycythaemia vera and in 50-60 % of patients with essential thrombocythaemia and primary myelofibrosis (Ferreira Cristina et al., 2018[4]).