and K.L.G. 2-[3-(1,3-dicarboxy propyl)ureido] pentanedioic acid61. Those prodrugs utilized a disulfide linker to enable RGS9 drug release in the reducing environment of the cytoplasm. Some of the tested drugs exhibited cytotoxicity to PSMA-expressing LNCaP cells at single- or double-digit nanomolar concentration levels. However, in vivo safety and efficacy of those drugs have not been tested. […]