BTG1 and acute lymphoblastic leukemia: In addition, the finding that BTG1 deletions are enriched in distinct high‐risk ALL subgroups, such as BCR‐ABL1, and BCR‐ABL1‐like ALL, and are correlated with poor outcome in IKZF1‐deleted ALL (Scheijen et al., 2016), requires further investigation to carefully examine the specific contribution of BTG1 copy number losses to disease progression in these ALL subtypes.