AICDA and acute lymphoblastic leukemia: To elucidate whether BCP-ALL-cells may indeed acquire such AID-mediated survival advantages, we searched for evidence of AID activity in BCP-ALL patients employing three strategies: (1) mutational signature analysis in clustered mutations, (2) analysis of mutations in known AID-target genes, and (3) identification of alternative AID-target genes in the precursor B-cell context.