ANPEP and cancer: Therefore ketoprofen as a non-selective cox Inhibitor was conjugated with linear RGD and NGR to take advantage of targeting capability of these two motifs and delivering ketoprofen to these cancer cells with overexpression of integrin and aminopeptidase N. In order to investigate the impact of possible steric hindrance due to the attachment of the drug to the peptide, a linear six carbon (hexanoic acid) linker was also used as a spacer.