COL5A1 and familial pancreatic carcinoma: Previous studies have shown that selective deletion of type I collagen (Col1) in pancreatic cancer myofibroblasts leads to the upregulation of Cxcl5 in cancer cells and suppression of CD8+ T cells.[36] To investigate whether Ccn1 promotes chemokine expression through the regulation of collagen, we examined the effects of Col5a1 overexpression in Ccn1‐deficient KPC cells.