JAK2 and myeloproliferative neoplasm: The driver mutation strongly correlated with a higher act-PLT binding to CD3+/CD56+ (R2 = 0.24; p=0.001) and CD8 T cells (R2 = 0.19; p = 0.004), with JAK2-mutated patients displaying lower frequencies of aggregates compared to CALR-mutant MPN (regression models in Supplemental Table 2).