With regards to large-scale copy number aberrations, trisomy 21 was moderately enriched in Late-Pro leukemias (n = 5/22, 23%; P = 0.020; Supplementary Fig. 13) and was found to be mutually exclusive with IKZF1 losses (FDR-adjusted P = 0.039; Supplementary Table 7). This evidence concerns the gene IKZF1 and leukemia.