Cytogenetics and genetics are necessary to distinguish between Philadelphia chromosome/BCR-ABL1 positive (Ph+) and Ph- ALL, or identify other high-risk abnormalities such as t(4;11)/KMT2A rearrangements, monosomy 7, hypodiploidy and IKZF1 gene deletion. This evidence concerns the gene IKZF1 and acute lymphoblastic leukemia.