Although radioiodine provides the historical foundations of theranostics, the prototype RLTs include 68Ga-DOTATATE and 177Lu-DOTATATE, which target somatostatin receptor subtype 2 in neuroendocrine tumors, and 68Ga-PSMA-617 and 177Lu-PSMA-617, which target prostate cancer. This evidence concerns the gene FOLH1 and neuroendocrine neoplasm.