In mice xenografted with RKO colon carcinoma cell inhibitors of BRAF and MDM4, a nuclear protein structurally homologous to MDM2 that interacts with both p53 and MDM2, this treatment managed to shrink the tumor by 80%, when the response to each drug tested separately was 23% and 24%, respectively [77]. The gene discussed is BRAF; the disease is colon carcinoma.