As regards the localization of bleeding events among PMF patients, 20% of IDH mutant PMF patients experienced gastrointestinal bleeding and 20% intracranial hemorrhage, while gastrointestinal hemorrhage occurred in 5.6% and intracranial hemorrhage in 1.4% of IDH wild-type PMF patients (P = 0.061). This evidence concerns the gene IDH1 and intracranial hemorrhage.