In addition, expressed on professional antigen-processing cells (APCs), such as DCs, macrophages, and B cells, class II MHC molecules (MHC-II) present exogenous peptides to activate CD4 + T cells.88,89 Despite substantial research on MHC-I and tumor immunotherapy, recent studies have shown that tumor-specific MHC-II molecules are also associated with favorable outcomes in patients with cancer.90 MHC IIIs are not markers on the cell surface and are not discussed here. This evidence concerns the gene HLA-C and neoplasm.