GNB1 and myelodysplastic syndrome: In between, mutations in TP53, SF3B1, SRSF2, GNB1, and CBL were identified with similar frequencies in both cohorts (e.g., TP53; 4 vs. 5%, P = 0.11), and such cases will be denoted as overlapping MDS patients, whereby founder mutations lead to directly to MDS or indirectly though CH.