PTGS2 and neoplasm: CRC-associated microbiota promote tumor growth via toxins that damage host DNA and activate signaling pathways including STAT3, NF-κB, Wnt, and SREBP-2, thereby inducing COX-2 expression and creating an inflammatory microenvironment enriched with reactive oxygen species (ROS) and reactive nitrogen species (RNS), ultimately enhancing immune evasion and metastatic potential (132, 133).