(A) Neutrophils expressing JAK2-V617 have increased activation of β1 and β2 integrin, resulting in increased adhesion to VCAM and ICAM1 on the vascular endothelium and enhanced thrombus formation. JAK2-V617 enhances activation of Rap1, which then translocates to the plasma membrane, thereby inducing the inside-outside signaling that shifts β integrins from a closed, low-affinity confirmation to a high-affinity confirmation (inset). (B) Antibodies targeting β1 and β2 integrin reduce neutrophil adhesion, resulting in decreased thrombus formation.