Several proteins have been reported to be potential biomarkers or therapeutic targets in canine oral tumors, such as melanoma cell adhesion molecule, cluster of differentiation 146 (CD146), Ras GTPase-activating-like protein IQGAP1, programmed death ligand-1, leptin, fascin-1, chondroitin sulfate proteoglycan-4 in OM, proliferating cell nuclear antigen, p63 and E-cadherin, high mobility group A2 in OSCC, and CD46 in ameloblastoma [10–19]. The gene discussed is MCAM; the disease is ocular melanoma.