FOLH1 and prostate cancer: Recently, [<sup>161</sup>Tb], a radiolanthanide introduced for treating micrometastatic foci, has shown great promise for treating prostate cancer.<h4>Results</h4>In this study, Terbium-161 [<sup>161</sup>Tb]Tb was radiolabeled with prostate-specific membrane antigen (PSMA)-617 ([<sup>161</sup>Tb]-PSMA-617) and the therapeutic efficacy of the radiolabeled compound investigated <i>in vitro</i> and <i>in vivo</i>.