PTGS2 and squamous cell carcinoma: In dogs, the expression of COX-2 has been reported in many types of cancers, such as mammary tumors, prostatic carcinoma, transitional cell carcinoma, squamous cell carcinoma, intestinal epithelial tumors, nasal epithelial tumor, renal cell carcinoma, oral melanomas, osteosarcomas, and meningiomas [17].