Amplifications of chromosome 21 are one of the most highly recurrent copy number alterations found in approximately 39% of children with non-DS AMKL, possibly because certain chromosome 21 genes (e.g., DYRK1A [dual specificity tyrosine phosphorylation regulated kinase 1A] and ERG) act as critical players in megakaryopoiesis (de Rooij et al., 2017; Li and Kalev-Zylinska, 2022). The gene discussed is DYRK1A; the disease is acute megakaryoblastic leukemia.