PAX5^P80Rmutation defines a subtype of BCP-ALL with distinct transcriptional signature and genomic alterations. (A) Unsupervised hierarchical clustering of RNA-seq gene-expression data of 170 BCP-ALL cases. The color coding of genetic annotations is indicated at the bottom of panel A. (B) Structural modeling of PAX5 P80R mutation based on the crystal structure of the paired box DNA binding domain of PAX5 (PDB 1K78²¹ ). The Pro80 mutated to Arg (indicated in green) is located in the linker nearby the N-terminal helix. The PD is depicted in blue; the DNA helix is depicted in orange. (C) Gene Set Enrichment Analyses of genes expressed in PAX5^P80R cases as compared with other cases. Gene Set Enrichment Analyses show negative enrichment of PAX5 target genes upregulated during early stages of B-cell differentiation (upper left) and positive enrichment of MYC target genes (upper right), E2F target genes (lower left), and MTORC1 signaling genes (lower right). (D) Genomic alterations of the 30 PAX5^P80R cases. The color-coding is indicated at the bottom of panel D. FDR, false discovery rate; NES, normalized enrichment score.