The Regulation of INK4/ARF in Cancer and Aging

Loss of the INK4a/ARF/INK4b locus on chromosome 9p21 is among the most frequent cytogenetic events in human cancer. The products of the locus—p15INK4b, p16INK4a, and ARF—play widespread and independent roles in tumor suppression. Recent data also suggest that expression of p16INK4a induces an age-dependent decrease in the proliferative capacity of certain tissue-specific stem cells and unipotent progenitors. Here, we discuss the regulation and role of p16INK4a, ARF, and p15INK4b in cancer and aging.