Strikingly, this IGH germline ALL group exhibited a high frequency of IKZF1 deletions and non-V(D)J rearrangements including CRLF2-IGH, EPOR-IGH, and EBF1-PDGFRß that can be exploited as leukemia-specific targets in clinical diagnostics of MRD. This evidence concerns the gene IKZF1 and leukemia.