Co-mutations in well-known leukemia driver genes, such as DNMT3A and TET2, are frequently reported, along with mutations in ASXL1, NRAS, SF3B1, and SRSF2. In this context, UBA1 could represent the primary clone, a subclonal event in combination with known leukemia driver mutations, or a secondary main driver event following treatment [3, 6, 19]. The gene discussed is UBA1; the disease is leukemia.