First, in B-ALL case #03 with complex karyotype and BCR::ABL1 fusion, OGM detected infrachromosomal deletions characteristic of B-ALL, namely recurrent deletions in IKZF1, PAX5, BTG1, ADD3 genes, and CDKN2A biallelic deletion (Figure 4) [21]. Here, BTG1 is linked to precursor B-cell acute lymphoblastic leukemia.