Rather, the targeting potential of a nanoparticle is determined by an optimized combination of surface chemistry, PEGylation, and antibody density.180 The anti-PSMA mAb J591 has also been used for targeted delivery of docetaxel-loaded superparamagnetic iron oxide nanoparticles (SPION) to prostate cancer cells.181 J591-SPION-DTX exhibited a significantly higher uptake in prostate cancer C4-2 (PSMA+) cells compared to PC-3 (PSMA−) cells. This evidence concerns the gene FOLH1 and prostate carcinoma.