In another study, distorted square planar copper(II) complexes (20) synthesized as Schiff base derivatives of nimesulide were found to have a significant cytotoxic effect on both pancreatic tumor cell lines BxPC-3 (COX-2 positive) and MiaPaCa (COX-2 negative), with IC50 values of 3 to 26 μM for the COX-2-positive cell line and 5 to 9 μM for the COX-2-negative cell line, which was more remarkable compared with nimesulide with IC50 values of 35 μM for the COX-2-positive cell line and more than 100 μM for the COX-2-negative cell line. The gene discussed is PTGS2; the disease is pancreatic neoplasm.