Ruben Mesa, MD, FACP, from the Mayo Cancer Clinic Center, Rochester, MN, USA, talks to us about the impact of the COMFORT I-II studies (NCT00952289) (NCT00934544) on uncovering the role and importance of cytokines with the symptoms and disease severity of myelofibrosis. He adds that this information may aid in investigating the benefit of JAK inhibition in reducing splenomegaly in myelofibrosis and potentially improving patient outcomes. This interview was filmed at the European Hematology Association (EHA) 2017 Annual Congress in Madrid, Spain.