with a high risk of developing colorectal cancer. There is a need for a molecular marker that would predict the colorectal cancer associated with UC. Microsatellite instability (MSI) has been detected in colorectal cancers associated with UC. Some reports in the literature show the presence of MSI in the neoplastic and non-neoplastic severe inflammatory mucosa of UC. The aim of this study was to assess whether MSI is present in non-neoplastic mild to moderate inflamed mucosa in UC.