Further, NF-κB is a critical transcription factor of M1 macrophages, regulating the expression of a variety of inflammatory genes, including those encoding IL-6, IL-1β, MCP-1, and cyclooxygenase-2 (COX-2), shown to play important roles in obesity-related PDAC promotion [55]. Here, PTGS2 is linked to obesity due to melanocortin 4 receptor deficiency.