SERPINB3 and breast neoplasm: Additional gene set enrichment analysis (GSEA) revealed the significant upregulation of 374 MYC signature genes,28,29 defined by their MYC binding sites, and a basal-like gene expression profile30 derived from human breast tumors, in the transcriptome of SERPINB3-high and basal-like/squamous PDAC tumors (see enrichment plots in Figures 2B and 2C).