Acute lymphoblastic leukemia (ALL) is now being reclassified into newly identified subtypes due to genetic abnormalities, Philadelphia chromosome‐like B‐lineage ALL is one of the new high‐risk subtypes characterized by genetic alterations that activate various signaling pathways, including those involving cytokine receptors, tyrosine kinases, and epigenetic modifiers. Philadelphia chromosome‐like ALL is essentially heterogeneous; however, deletion mutations in the IKZF1 gene encoding the transcription factor IKAROS underlie many cases as a key factor inducing aggressive phenotypes and poor treatment responses. WGS (whole genome sequencing) studies of ALL patients and ethnically matched controls also identified inherited genetic variations in lymphoid neoplasm‐related genes, which are likely to increase ALL susceptibility. On the contrary, Genome editing technologies offers new opportunities for tackling diseases, and genome-editing tools such as CRISPR-Cas9 are an important means of advancing functional studies of ALL through the incorporation, elimination, and modification of somatic mutations. These findings are directly relevant to clinical hematology, and further studies on this aspect could contribute to accurate diagnosis, effective monitoring of residual disease, and patient‐oriented therapies.