In contrast, the tumor suppressor E2F target genes, such as ARF and TAp73, which have atypical E2F response elements (GC repeats), are specifically activated by deregulated E2F activity induced by forced inactivation of RB, which mimics dysfunction of the RB pathway, but not by growth stimulation-induced physiological E2F activity [38,39]. The gene discussed is CDKN2A; the disease is neoplasm.