We thank Drs Gustavo Leone and Antony Trimboli (Ohio State University) for E2F1−/−E2F3a−/− mice, Norman E. Sharpless (University of North Carolina) for p16−/− mice, Kimie Nomura and Tomoyo Kakita (Japanese Foundation for Cancer Research) for histology, Sachiko Noda (Japanese Foundation for Cancer Research) for animal care and Yo-ichi Nabeshima (Institute of Biomedical Research and Innovation) for valuable suggestions. Here, CDKN2A is linked to cancer.