NOS2 and pancreatic ductal adenocarcinoma: However, NO generated by the inducible NOS (iNOS or NOS2) and the co-expression of iNOS with mitochondrially encoded cytochrome c oxidase II (MT-COII or COX2) may lead to a particularly aggressive cancer phenotype of breast, liver, colon, pancreatic ductal adenocarcinoma, and hepatocellular cancers [7].