BTG1 and acute lymphoblastic leukemia: Our results showed that most of the IKZF1 Δ1-8 derive from large interstitial deletions within chromosome 7, spanning genes either upstream (ZPBP and C7orf72, ~210 Kb upstream of IKZF1) or downstream (FIGNL1 and DDC, 39 and 53 Kb downstream, respectively) of IKZF1. Interestingly, EBF1 and BTG1 deletions were found in patients with intragenic IKZF1 deletions, but they were rarely deleted in the cohort of IKZF1 Δ1-8 patients, corroborating with a previous report showing that BTG1 and EBF1 deletions co-occur in ALL [13].