Thus, a number of IgG1 mAbs, such as Trastuzumab, Cetuximab and Rituximab, directed against the HER-2/neu, EGF-R, or the B cell-restricted antigen CD20, have been developed and were used for the treatment of different tumor types, such as colorectal cancer (CRC), head and neck squamous cell carcinoma (HNSCC), Non-Hogkin lymphoma and chronic lymphatic leukemia (CLL), respectively. This evidence concerns the gene EGFR and head and neck squamous cell carcinoma.