To investigate contributions of the p53/Toca-1 axis to breast cancer progression and mestastasis, we performed mammary orthotopic xenograft assays using MTLn3 control, sh-p53 and sh-p53/sh-Toca-1 cells in Rag2−/−:IL2Rγc−/− mice. The gene discussed is RAG2; the disease is breast carcinoma.