PPBP and familial pancreatic carcinoma: Herein, we determined that the expression of C-X-C motif chemokine ligand 8 (CXCL8), CXCL6, CXCL4L1, CXCL1, CXCL4, CXCL7, CXCL5, CXCL3 and CXCL2 was up-regulated, whereas CXCL9, CXCL10 and CXCL11 were down-regulated in pancreatic cancer cells compared with normal duct epithelial cells and further uncovered that four enhancer elements showed robust interaction to form DNA looping containing the up-regulated eight CXCL genes, whereas the other enhancer controlled CXCL9, CXCL10 and CXCL11 to form another DNA loop.