A Zombie LIF Gene in Elephants Is Upregulated by TP53 to Induce Apoptosis in Response to DNA Damage

Larger organisms with increased cell counts have a theoretically increased risk of cancer; the observation that larger species do not seem to have an increased cancer risk in contradiction to the patterns observed between members within species is known as Peto's Paradox. ere, we show that elephants and their extinct relatives (proboscideans) may have resolved Peto’s paradox in part through refunctionalizing a leukemia inhibitory factor pseudogene (LIF6) with pro-apoptotic functions. LIF6 is transcriptionally upregulated by TP53 in response to DNA damage and translocates to the mitochondria where it induces apoptosis.