["Mutations in the tumor suppressor gene p53 are associated with neoplasia in ulcerative colitis, but little is understood of their significance in Crohn's disease (CD).", 'To explore p53 expression as a marker of neoplasia in CD patients.', 'This is a retrospective review of CD patients who underwent p53 IHC staining in our center between 1995 and 2003. The p53 status was correlated to the presence and grade of neoplasia at the time of staining and in subsequent follow-up.', 'Fourteen CD patients had p53 assessment: eight were p53 positive and six were p53 negative. Seven of eight p53+ had dysplasia (six LGD, one HGD); one of six p53-had dysplasia (LGD) (P = 0.03). Four p53+ patients with follow-up had persistent dysplasia and two had progression to a higher grade. Three p53- patients with follow-up remained free of dysplasia.'] Are p53 mutations associated with dysplasia and progression of dysplasia in patients with Crohn 's disease?