In a study from Lahore, only two JAK2V617F negative patients were found to have mutations in JAK2 exon 12.25 MPL and JAK2 exon 12 mutations were also not identified in a study from Rawalpindi.29 However, the frequency of JAK2 mutation in PV, ET, and PMF patients is lower than reported worldwide. Here, JAK2 is linked to acquired polycythemia vera.