KMT2A and acute lymphoblastic leukemia: ALL genomic analysis in clinical practice is frequently conducted through the so-called “low-throughput techniques” (e.g., fluorescence in situ hybridization—FISH), which allow investigation of the most frequent abnormalities for ALL subtypes classification (ETV6–RUNX1 fusion, TFPT–PBX1 fusion, BCR–ABL1 fusion; MLL fusions).