We also assessed both the organ specificity of disseminated lesion and the mechanism of late-onset recurrence of gastric cancer by immunohistochemistry using pan-CK, CK-7, and CK-20 as a indicator of epithelial differentiation [13-16], p53 as a chemo-radioresistance marker [17], PCNA, and Ki-67 as a cell proliferation marker [18,19]. This evidence concerns the gene PCNA and gastric cancer.