[pfdietz]

Elephants have 100x as many cells as a human does, live about as long, but have about 1/2 the chance of dying of cancer. Why? A big part is that each elephant cell has ~40 copies of the p53 gene.

[hawk_]

Before anyone thinks of increasing p53 in human bodies to prevent cancer keep in mind that it can cause premature aging.

[pfdietz]

I'm sure elephants have all sorts of compensatory mutations so they can live with so many copies of the gene.