MIR17HG and Chr8q are gained in mBL. (A) Frequency of DNA CN gains found in adult (red-orange) or pediatric (blue) mBL for MIR17HG and paralogues MIR106B and MIR106A. (B) Heat maps of expression of the MIR17∼92 cluster members measured by TaqMan Array Human MicoRNA A Card (ABI) in tumors with and without MIR17HG DNA copy number gain. (C) Validation of the frequency of MIR17HG DNA CN gain in adult-BL using a published BL genomic/WES dataset. CN status was assessed using Varscan2 CNV followed by segmentation by the Circular binary segmentation algorithm. For WES data, regions of gain were cut off at a threshold of 0.2 log₂ ratio. (D) Copy number status of MIR17HG and paralogues for individual tumors (gain = red, loss = green). (E) Kaplan-Meier curves comparing overall survival adult-mBL cases by MIR17HG copy number status. Several MIR17HG gain/amplified cases also had double MYC/ BCL2 translocation/mutation, but showed BL mutation and GEP profile. (F) Plot of CNAs along chromosome 8 for mBL cases with abnormalities. (G) Bar graph of the fold increase in expression of genes along chromosome 8 that are significantly upregulated (P < .05, 1-sided Student t test) in cases with CN gain. Genes of interest are noted. (H) Boxplot of MYC mRNA expression by MYC DNA copy number status and by age. Red points represent expression values of individual cases. Expression levels in normal centroblasts (CB), CD77-negative cells, and naive B cells (NBC) are noted for comparison. (I) MYC protein expression in 3 cases with MYC gain and 3 cases with a MYC DNA copy number=2. (J) Signatures upregulated on MYC overexpression were enriched in pediatric-mBLs compared with adult-mBLs.