PTGS2 and neoplasm: Ratios of COX-2 mRNA expression (tumor/normal) normalized with respect to tissue weight were not associated with gender (men vs. women, P = 1.0), tumor localization (left sided vs. right sided colon, P = 0.37), tumor grade (T2 vs. T3, P = 0.80; T2 vs. T3/T4, P = 0.57) or lymph node metastases (0 vs. N1/N2, P = 0.14).