A prostatic intraepithelial neoplasia-dependent p27Kip1 checkpoint induces senescence and inhibits cell proliferation and cancer progression: Majumder PK, Grisanzio C, O'Connell F, Barry M, Brito JM, Xu Q, Guney I, Berger R, Herman P, Bikoff R, Fedele G, Baek W-K, Wang S, Ellwood-Yen K, Wu H, Sawyers CL, Signoretti S, Hahn WC, Loda M, Sellers WR, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA