In a previous study, tumor cells were suggested to evade the host immune response which might be due to the following mechanisms: (a) impaired antigen presentation of the tumor cell surface lowers the capacity of T-cells to recognize the decrease in tumor cells, (b) mutation of the major histocompatibility complex (MHC) or antigen-processing genes decreases the capacity of T-cells to recognize tumor cells, and (c) production of immunosuppressive proteins inhibits T-cell activation [27]. This evidence concerns the gene HLA-C and neoplasm.