This revealed 314 DEGs for HNSCC, 323 for PDAC, and 190 for STAD common in at least three datasets from the same cancer type, of which 18 genes were common to all cancers analyzed (Figures 2A–H; Supplementary Tables S2, S3), which were BGN, CDH11, COL1A1, COL1A2, COL3A1, COL5A2, ECT2, FAP, FN1, HPGD, IGF2BP3, INHBA, MMP11, NOX4, PLAU, SPARC, SULF1, and THBS2. To identify potential dysregulated processes and pathways in PDAC, HNSCC, and STAD, a Gene Ontology (GO) analysis was performed using DEGs common in at least three datasets for each cancer type. This evidence concerns the gene COL5A2 and cancer.