JAK2 and acquired polycythemia vera: Additionally, individuals with the JAK2 46/1 germline risk haplotype (GGC, from rs3780367, rs10974944, rs12343867, Methods section) were substantially more likely to acquire JAK2V617F mutations (OR = 2.69, 95% CI = 2.02-3.58, P = 1.16 × 10−11), with 634 (68.61%) individuals carrying the JAK2 46/1 germline risk haplotype, and post-polycythemia vera MF (88.15%) having a higher frequency than both primary MF (65.98%) and post-essential thrombocythemia MF (66.45%).