JAK2 and myeloproliferative disorder: This haplotype is described as one of those responsible for the processes that precede the acquisition of JAK2V617F, increasing the mutation rate of the JAK2 locus and the probability of acquiring mutations with selective advantage, which is the case of JAK2V617F and which, in turn, causes clonal myeloproliferative disorders [31,45,46,47,48].