ERBB2 and neoplasm: To test the effects of FGFR inhibition using AZD4547 in MMTV-ErbB2 mice, we used a prevention model to administer AZD4547 (0, 2, or 6 mg/kg/day) for 10 weeks until the mice reached 18 weeks of age, which is during the premalignant ‘risk window’ of tumor development.