On the seventh day, the group supplemented with glycine presented clinical and laboratory resolution (i.e., absence of inflammatory infiltrate on histological examination and reduction of lipid peroxidation) (p < 0.001), indicating the cytoprotective and anti-inflammatory effect of glycine in the oral mucosa.We studied the effect of glycine supplementation on the amount, types of collagen, epidermal growth factors (EGF), and platelet derivative (PDGF) in experimental mucositis. The gene discussed is EGF; the disease is mucositis.