F2RL1 and irritable bowel syndrome: DRG neurons of PAR2−/− mice exposed to supernatants from IBS patient colon biopsies did not show any increase in calcium mobilization ex vivo. Biopsy supernatants from IBS patients also caused thermal hyperalgesia, allodynia, and abdominal contractions in WT mice but did not cause hyperalgesia or abdominal contractions in PAR2−/− mice.