Main characteristics of studies involving in the meta-analysis.

<p>Abbreviations: MDS, myelodysplastic syndromes; WHO, World Health Organization; FAB, French American British classification; RA, refractory anemia; RARS, RA with ringed sideroblasts; RCMD, refractory cytopenia with multilineage dysplasia; RAEB, RA with excess blasts; RAEB-t, RAEB in transformation; IPSS, International Prognostic Scoring System; <i>IDH</i>, <i>isocitrate dehydrogenase</i>.