Overall characteristics of patients and stratification according to serum miR-21 level.

Abbreviations: miR-21, microRNA-21; WHO, World Health Organization; RA, refractory anemia;RARS, RA with ring sideroblasts; RCMD, refractory cytopenia with multilineage dysplasia; RCMD-RS, RCMD with ring sideroblasts; RAEB, refractory anemia with excess blasts; MDS-U, myelodysplastic syndromes unclassifiable; PB, peripheral blood; BM, bone marrow; HMA, hypomethylating agent; IPSS, International Prognostic Scoring System; NA, not available; WPSS, WHO classification-based Prognostic Scoring System; alloHCT, allogeneic hematopoietic stem cell transplant, INT, intermediate.aCytogenetic: Good = normal, -Y alone, del(5q) alone, del(20q) alone; Poor = complex (≥3 abnormalities) or chromosome 7 anomalies; Intermediate = other abnormalities.bAt least 2 units of red blood cell transfusion during 8 weeks prior to HMA initiation.