PAK1 and gastric cancer: We found that there were significant differences of Rac1, Pak1 and Rock expression in gastric cancer, epithelial neoplasia and normal epithelial tissue, which was an early molecular event in gastric cancer; Rac1, Pak1 and Rock expression, closely related to lymph node metastasis, depth of invasion and degree of differentiation, were valuable indicators in evaluating the degree of malignancy in gastric cancer and thus could contribute to the predication of invasion and metastasis of gastric cancer.