A significant association found with higher COX-2 mRNA expression in negative-ER and in higher Ki67 protein levels in hIMPC, as well as the COX-2 protein expression also related with higher Ki67 protein levels in hIMPC, sustaining the COX-2 involvement in breast tumors with poor characteristics (28, 31, 32). The gene discussed is PTGS2; the disease is breast neoplasm.