MLH1 and colorectal carcinoma: In conclusions, although further longitudinal studies with large numbers of subjects are needed to clarify the role of methylation status of APC, CDH13, MGMT, MLH1 and RUNX3 in non-neoplastic mucosa as a marker of UC-associated CRC, and to validate the predictive power and clinical value of analysis of the number of methylated genes, these preliminary results could allow for the adjustment of a patient's surveillance interval and to select UC patients who should undergo intensive surveillance.