ERBB2 and breast neoplasm: Utilizing a longer-lived radionuclide, 225Ac (t1/2 = 10.0 d), in the HER-2/neu-targeted RIC at its maximum tolerated dose prevented metastatic breast tumor formation in over half of the treated mice, while the irrelevant control, 225Ac-RIC, had no effect against metastatic tumor development [21].