HER2 and EGFR amino acid sequence in canine mammary carcinoma had 92% and 91% homology with the human counterpart, respectively, and carried the binding sites of trastuzumab (anti-HER2) and cetuximab (anti-EGFR) monoclonal antibodies [85], suggesting the importance of developing homologous “caninized” antibodies to be used in canine patients. The gene discussed is EGFR; the disease is breast carcinoma.