To investigate the relationship between HMGB1 and mucosal immunity or mucosal differentiation in UC-associated carcinogenesis, we examined mucosal immunity using four systems: a mouse colon carcinogenesis model, a mouse colitis carcinogenesis model, samples of human colitic carcinoma, and samples of human hyperplastic mucosa surrounding colon cancer. This evidence concerns the gene HMGB1 and colitis.