FOLH1 and prostate carcinoma: MMAE was selected as the chemotherapeutic drug because of its high potency 70, its wide use in antibody drug conjugates 71, its synergy with PDT 72 and the fact that we have successfully targeted it to PSMA for the treatment of prostate cancer with a greater therapeutic index when compared to a PSMA-targeted antibody drug conjugate using MMAE 60.