In pancreatic cancer, tolerance to tumor Ag may occur due to Ag persistence, downregulation of major histocompatibility antigens (MHC) which prevents effective Ag presentation or increased infiltration of cells with immunosuppressive properties such as Ag-specific regulatory T (Treg) cells, tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs) and tumor-associated fibroblasts.33,34. The gene discussed is HLA-C; the disease is neoplasm.