In total, 48 high hyperdiploid and 41 ETV6/RUNX1-positive cases were investigated; the cohort analyzed with MS comprised eighteen high hyperdiploid and nine ETV6/RUNX1-positive pediatric ALL cases, as ascertained by chromosome banding, fluorescence in situ hybridization (FISH), SNP array analysis and reverse transcriptase-PCR for the fusion transcript (Fig. 1a and Supplementary Data 1 and 2). The gene discussed is RUNX1; the disease is acute lymphoblastic leukemia.