 The study will include a phase of 3 weeks 7 days administration of sitagliptin as monotherapy taken orally after liver biopsy and before HCC resection. The window of 7 days is deliberately wide to take in account the variable arrangements made for surgical resection. Nevertheless we will make our efforts to focus on a three weeks regimen. Three doses of sitagliptin will be used: 1 100mgday dose recommended in the SmCP, 2 200mgday and 3 600mgday; with 5 patients in each group. Arrangements will be made for surgical resection upon standard care. Blood samples will be obtained for immunology studies at each visit. The study will end one week after surgery or less if the state of health of the patient does not require to stay longer in the hospital. Patients will continue their treatment for HCC as prescribed by the clinician. 