To determine if PEAK1 regulates VEGFA-induced angiogenesis and tumor growth, we developed a syngeneic mouse model of breast cancer using Peak1−/− null mutant and Peak1+/+ wild type mice and the E0771 breast cancer cell line derived from a spontaneous medullary breast adenocarcinoma in C57BL/6 mice with mutated p5327. The gene discussed is PEAK1; the disease is breast cancer.