FCGRT and neoplasm: LNCaP-AR tumor bearing animals were treated with the (a) specific [225Ac]hu11B6 drug, (b) specific but non-internalizing [225Ac]hu11B6-H435A (this mutated antibody targets hK2 expressing cells but is inhibited from internalization via FcRn-coupled cellular processes by exchanging histidine 435 to an alanine), or (c) non-specific [225Ac]huIgG1 control antibody.