FOLH1 and metastatic prostate carcinoma: The most important examples are radioactive iodine (131I) therapy, which is used in the treatment of patients with well-differentiated thyroid cancer [1–4], and prostate-specific membrane antigen (PSMA)-targeted radioligand therapy, for patients with metastatic prostate cancer using [177Lu]Lu- or [225Ac]Ac-PSMA ligands [5–10].