Mucusinteracts with defensive factors such as NO, PGE2, and EGF to sustainthe integrity and form the primary defense of the gastric mucosa.137,151 In animal models of gastric ulcers, the contents of PGE2, EGF, vascularendothelial growth factor (VEGF), basic fibroblast growth factor (bFGF),and NO in gastric tissue were significantly reduced. This evidence concerns the gene EGF and gastric ulcer.