Stephen Oh, MD, PhD, Washington University School of Medicine, St. Louis, MO, discusses driver mutations for myeloproliferative neoplasms (MPNs) such as JAK2, CALR, and MPL, all of which result in some degree of activation of the JAK/STAT signalling pathway. Dr Oh also talks on the impacts of secondary mutations such as splicing mutations that play a role in the pathogenesis of MPNs, highlighting their prognostic implications. This interview took place at the Texas MPN Workshop: Second Annual Workshop and Meeting in 2021.