SF3B1 and hematologic disorder: Considering the importance of Tregs in controlling immune responses, we determined how hematological malignancy-associated Sf3b1 mutation, Sf3b1-K700E in this case, affects the Tregs by using mice that express Sf3b1-K700E specifically in Tregs (Sf3b1K700Efl/+/Foxp3YFP-Cre).