HLA-C and neoplasm: While the first requires the presentation of tumor-associated antigens (TAA)-derived peptides in major histocompatibility (MHC) class I- and II-proteins (HLA-A, B or C and DP, DQ or DR, respectively) for activating T cells and their proliferation, the second requires the presence of TAA-derived peptides in MHC to allow for deleting tumor cells.