- The tumor suppressor gene Brca1 is required for embryonic cellular proliferation in the mouse. Hakem, R., de la Pompa, J.L., Sirard, C., Mo, R., Woo, M., Hakem, A., Wakeham, A., Potter, J., Reitmair, A., Billia, F., Firpo, E., Hui, C.C., Roberts, J., Rossant, J., Mak, T.W. Cell (1996)