CNR2 and irritable bowel syndrome: The Q63R mutation in the CNR2 gene, encoding CB2, impairs endocannabinoid-induced inhibition of T cell proliferation.44 In an Italian paediatric IBD cohort, this mutation was associated with a more severe disease phenotype and shorter time to relapse for UC,45 but these were not replicated in a Turkish cohort of adult patients.46 This may be due to either age or ethnic differences between patients.