While LMP2 caspase-like activity was reduced both in IBS and Crohn’s disease patients, trypsin-like (MECL1) activity was increased more in IBS compared to Crohn’s disease and control patient samples, and the chymotrypsin-like activity (LMP7) was upregulated in Crohn’s disease patients only [67]. This evidence concerns the gene PSMB9 and Crohn disease.