IKZF1 and acute lymphoblastic leukemia: On one hand, the UK group on ALL study suggests that CDKN2A/B losses have no impact on outcome [58], while on the other hand, analysis of smaller series of Ph− patients suggests that CDKN2A/B deletions could be a marker of poor outcome, especially concomitantly with IKZF1 [63,68,80] or RB1 deletions [44], as has been shown in pediatric cohorts [109].