Comparison of CN profile and genetic features of adult and pediatric LBCL-IRF4 cases. (A) Comparative plot of CN and CNN-LOH between 7 LBCL-IRF4 cases in adults and 20 LBCL-IRF4 cases in the pediatric population. No significantly different regions were identified. (B) GEP and mutational comparison between LBCL-IRF4 in adults (n = 11) and previously published profiles in children (n = 17) showed ABC COO more often (P = .05) in adults, with higher mutational load (10.6 vs 4.7 mutations/case; Wilcoxon test, P = .004) and higher frequency of KMT2D, MYD88, and BTG2 (P < .05, marked with asterisk). (C) IRF4 mRNA expression levels obtained from the IRF4_NM_002460.1 probe on the Lymph2Cx assay. IRF4 mRNA levels in LBCL-IRF4 in children and adults was similar but higher when compared with DLBCL-AE without IRF4 rearrangement (17 570 vs 6948; Wilcoxon test, P ≤ .01). AE, aberrant expressor CD10⁺BCL6⁺MUM1⁺; R, rearrangement; wt, wild-type.