The BTG1 deletion identified in the present study, which occurs rarely in ALL patients but frequently co-occurs with ETV6::RUNX1 (Schwab et al, 2013), has been previously noted in analyses of REH using arrays (Tsuzuki et al, 2007) and PCR (van Galen et al, 2010), whereas NR3C1 has an established nonsense (p.Gln528Ter) mutation on one allele (Tamai et al, 2022) and a deletion on the other (Grausenburger et al, 2016). The gene discussed is BTG1; the disease is acute lymphoblastic leukemia.