Zhang and collaborators [51] were the pioneers in identifying NPM1 mutations in two MDS patients (5.2%), both of which were type A. Subsequently, Bains et al. [52] reported NPM1 mutations in seven MDS patients (4.4%), all falling under the refractory anemia with excess blasts category, and with a normal karyotype (p < 0.001). This evidence concerns the gene NPM1 and myelodysplastic syndrome with single lineage dysplasia.