Human PSMA-expressing PC-3 prostate cancer cells (PC3-PIP) and isogenic PSMA-negative control cells (PC3-Flu) were obtained from Dr. Warren Heston (Cleveland Clinic, Cleveland, OH) (19 (link)). Human PSMA-expressing LMD-MDA-MB-231 breast cancer cells (LMD-PSMA) and isogenic PSMA-negative control cells (LMD) were previously developed (20 (link)). Cells were cultured in RPMI 1640 (Corning Cellgro, Manassas, VA) plus 10% FBS (Sigma-Aldrich, St. Louis, MO), 50 μg/ml Gentamicin (Quality Biological, Gaithersburg, MD) and 5 μg/ml Ciprofloxacin (US Biological, Salem, MA). Cells were maintained at 37°C, 5% CO2 in a humidified incubator. Cells were authenticated by STR profiling (Johns Hopkins GRCF DNA services; November 2015) and confirmed > 90% homology with parental ATCC cell lines. Further mycoplasma monitoring occurs semiannually.