3. assessment of activation status of macrophages, dendritic cells, infiltrating lymphocytes evaluating surface markers (i.e.) and intracellular cytokines pattern (i.e. TNF , IFN , IL4, IL10) by cytofluorimetric analysis. Two biopsies will be subjected to gentle enzymatic digestion and then stained with properly labelled antibodies directed against surface antigens or intracellular cytokines.