EGF and oral mucositis: During chronic oral mucositis of mechanical, chemical, or microbial origin, leukocytes and macrophages are recruited in the damaged mucosa, where they produce cytokines such as interleukin-1, -6, and -8, tumor necrosis factors, transforming growth factor (TGF)-β1, and epidermal growth factor (EGF) [3] (Figure 1).