PTGS2 and breast cancer: Following systemic administration, FQ-CA-NPsenabled the codelivery of FQ and CA in orthotopic mammary tumors.ROS-dependent cargo release followed by fluorescence activation ofFQ in the tumor microenvironment allowed COX-2 binding for tumor accumulationand retention and detection of CA delivery into solid mammary tumors.The targeted codelivery of FQ and CA was confirmed by LC–MS/MSanalysis of tumor tissues, which was lowered significantly in animalspretreated with either an ROS-trapping agent (tempol) or a COX-2 inhibitor(celecoxib).