In our study of patients with co-mutation of SF3B1 and MPN driver mutations, we found that the VAF of SF3B1 mutations was greater than (a cutoff of at least 5%) or equal to the VAF of JAK2 or MPL mutations in almost 80% of patients, indicating that SF3B1 mutations might occur before JAK2 or MPL mutations in most patients with MDS/MPN-SF3B1-T [26]. The gene discussed is JAK2; the disease is myelodysplastic syndrome.