COL6A1 and pancreatic adenocarcinoma: TCGA analysis of TGF-β target genes (e.g., COL1A1, COL3A1, COL5A2, COL6A1, COL6A3, TIMP1, and CTGF) further identified overactivation of TGF-β signaling pathway in a broad spectrum of solid tumors, in particular in breast invasive carcinoma and pancreatic adenocarcinoma tissues (Supplementary Figs. 3–8).