Elephants' ability to resist cancer is a fascinating topic that has intrigued scientists for years. Despite their large size and long lifespans, which would theoretically increase their risk of developing cancer due to a higher number of cells and more time for mutations to occur, elephants have an unusually low cancer rate — less than 5%, compared to about 20% in humans.

Key Reasons Behind Their Cancer Resistance

1. Extra Copies of the TP53 Gene

   • Elephants have 20 copies of the TP53 gene, which is often referred to as the "guardian of the genome."
   • In contrast, humans only have 1 copy of this gene. TP53 plays a crucial role in detecting DNA damage and initiating cell repair or programmed cell death (apoptosis) to prevent cancerous growths.
   • The multiple copies of TP53 allow elephants to detect and eliminate potentially cancerous cells more effectively.

2. Efficient Apoptosis Mechanism

   • When elephant cells sense DNA damage, they tend to favor apoptosis (cell death) rather than attempting to repair the damage. This reduces the risk of a cell turning cancerous.
   • In humans, cells often try to repair DNA damage, which can sometimes lead to errors and increase the risk of cancer.

3. LIF6 Gene (Pseudogene Revival)

   • Elephants have a gene called LIF6, which was once considered a "dead" gene or pseudogene in other species. However, in elephants, it has been reactivated and plays a role in killing damaged cells.
   • LIF6 works in conjunction with TP53, adding an extra layer of protection against cancer.

Why Is This Important for Humans?

The unique cancer resistance of elephants has opened new avenues in cancer research. Scientists are studying these mechanisms to develop potential therapies and preventive strategies for human cancers. Understanding how elephants naturally suppress cancer could lead to breakthroughs in genetic engineering, targeted therapies, and improved treatments for cancer in humans.

This remarkable adaptation is yet another example of how evolution has equipped different species to thrive in their environments. For elephants, this trait helps ensure survival and reproductive success over their long lifespans.