REN and irritable bowel syndrome: These pathways encompass interactions between viral proteins and cytokines, natural killer cell cytotoxicity, cytokine signaling, the renin (REN)–angiotensin system, nucleotide metabolism, and the Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) signaling pathway, underscoring the complex interplay of immune and metabolic processes in IBS.