This first-reported case of SF3B1-mutated myelodysplastic/myeloproliferative neoplasm with thrombocytosis (MDS/MPN-SF3B1-T), harboring coexisting ASXL1, JAK2 p.R683G, and CBL mutations challenges conventional genomic prognostic paradigms. This evidence concerns the gene CBL and thrombocytosis disease.