 This peptide, when altered by intestinal transglutaminase, has a high density of overlapping T-cell epitopes.This increases the likelihood that the DQ2 isoform will bind and stay bound to peptide when recognised by T-cells.Gliadin in wheat is the best-understood member of this family, but other prolamins exist, and hordein (from barley), secalin (from rye), and avenin (from oats) may contribute to coeliac disease.