JAK2 and deep vein thrombosis: The risk of VTE was increased by 7.4-fold when the JAK2 allele burden is >20% (p = 0.004), 8.8-fold by 50% (p = 0.006) and there is a more significant risk with allele burden of >75% (p = 0.002), with mostly cases with proximal deep vein thrombosis (DVT) (p = 0.041) for allele burden of >50%.