However, the possible mechanisms leading to the up-regulation of CXCL5 in PC still remains unknown, despite previous studies on other cancers revealing that CXCL5 expression might be driven by multiple cancer-associated pathways, including nuclear factor-κB and cyclooxygenase-2/prostaglandin E2 [34,35]. This evidence concerns the gene CXCL5 and pachyonychia congenita.