For single-cycle treatments (37 kBq) of either anti-GPA33 225Ac-DOTA-PRIT or anti-HER2 225Ac-DOTA-PRIT, all treated mice showed complete response (CR; tumor volume ≤10 mm3) at approximately 20 d post-treatment; however, tumor escape was observed for most of the animals. This evidence concerns the gene GPA33 and neoplasm.