Several radioimmunoconjugates have been approved for cancer diagnosis, for example, arcitumomab (CEA-scan®), a 99mTc-labeled antibody fragment used for imaging of colorectal cancer, and capromab pendetide (ProstaScint®), an 111In-labeled mAb directed against prostate specific membrane antigen (PSMA) [78]. Here, FOLH1 is linked to cancer.