PCNA and cancer: In this study, PCNA expressions were increasing obviously from the intestinal mucosal cells (at 3 weeks) to the atypical hyperplastic intestinal mucosal cells (at 8 weeks), suggesting that PCNA levels were increased following with “inflammation–atypical hyperplasia–cancer” process, which is in line with a previous study.40 Aspirin could alleviate the expression of PCNA in atypical hyperplastic intestinal mucosal cells.