CNR1 and colitis: [47] A low BMI in CD patients is also considered to be an indicator of high disease activity. Therefore, 1359 A/A homozygosity could contribute to a more severe disease phenotype. This would be consistent with our results in CNR1−/− mice, demonstrating that these knockout mice take a more fulminate course in DNBS and DSS colitis. [3] However, functional experiments have to analyze if CNR1 signaling is indeed decreased in 1359 A/A homozygous patients.