FOLH1 and prostate cancer: Several other characteristics combine to make PSMA an ideal target for molecular diagnostics and therapeutics for prostate cancer: (1) it is overexpressed at all stages of the disease; (2) expression typically correlates with tumor grade, disease aggressiveness, metastasis and biochemical recurrence; (3) it is a transmembrane protein with an extracellular ligand-binding domain; and (4) the bound ligand-protein complex is internalized via receptor-mediated clathrin-dependent endocytosis [7, 8].