‐Anemia with erythroid lineage dysplasia‐≥15% BM RS‐Persistent thrombocytosis ≥450K‐Presence of SF3B1 mutation‐If not present, patient must not have history of cytotoxic or growth factor therapy‐No t(3;3), inv(3), del(5q)‐No history of myeloid clonal neoplasm (aside from MDS‐RS). This evidence concerns the gene SF3B1 and Thrombocytosis.