Both CDKN2A and CDKN2B, tumor suppressor genes encoding p16 (INK4a) and p15 (INK4b), respectively, which are localized to 9p21 and act via the Rb and p53 pathways, have been found to be aberrant to some degree in gliomas 21, 22. The gene discussed is CDKN2B; the disease is central nervous system cancer.