The CCK renders cyclotides very stabletoward chemical, enzymatic, and thermal degradation,55 and later, this remarkable stability was the basis forthe successful application of T20K in the experimental autoimmuneencephalomyelitis mouse model for multiple sclerosis via oral administration.19 Little is known about ADME properties of thedrug candidate T20K, but despite its stability, the peptide may eventuallybecome susceptible for proteolytic cleavage and break down to itsamino acid building blocks in the body. The gene discussed is CCK; the disease is multiple sclerosis.