Representation of unsupervised hierarchical clustering analyses including somatic mutations and current classification features according to WHO criteria within MDS without excess blasts. Diagnosis of each sample is shown by indicated colors. These analyses identified 3 main clusters: patients carrying the SF3B1 mutation, irrespective of current WHO classification criteria (MDS associated with SF3B1 mutation) (31 patients classified as RARS, 16 as RCMD-RS, 3 as RA, and 1 as RCMD according to WHO criteria) (left); patients with MD-associated mutations (mutations in genes involved in DNA methylation, splicing factors other than SF3B1, RAS pathway, and cohesin complex) classified as RCMD or SF3B1-negative RCMD-RS according to WHO criteria, as well as the 4 patients with unilineage dysplasia carrying mutation(s) in these genes (MDS with MD-associated mutations) (right); and all the patients with different mutation patterns (MDS NOS) irrespective of the presence of unilineage or MD (middle).