It is usually not detected and increases in the carcinogenesis processes, when cytokines, stimuli and tumor growth factors exist, and acting in association with neoplastic tumor cells, can regulate the initial growth of these cells, their proliferation, invasion, migration, angiogenic phenomena and finally apoptosis and programmed death of the cells19,21,27. In this study, the expression of Cox-2 was intense, at maximum level in most scars of animals with tumors from group A and group D. Expression was lower in group C. This evidence concerns the gene PTGS2 and neoplasm.