Blood cell JAKtivation aggravates cerebral venous thrombosis

In this issue of Blood Advances, Bourrienne et al present the first preclinical data on how the gain-offunction JAK2 V617F mutation that underlies most myeloproliferative neoplasms (MPNs) may modify outcomes in cerebral venous sinus thrombosis (CVST). Their study was spurred by observations that individuals harboring a hematopoietic JAK2 V617F mutation (irrespective of whether or not an overt MPN was present) have increased intracerebral hemorrhage (ICH) and worse outcomes with CVST.