While these findings argue for a more differentiated consideration of JAK2 V617F as diagnostic criterion for MPN (e.g., via a minimal required VAF), the cardiovascular risk—which is also a hallmark of JAK2-mutated MPN—is substantial in JAK2-mutated patients even if the diagnostic criteria for MPN are not met [41,42]. This evidence concerns the gene JAK2 and myeloproliferative neoplasm.