The gene P21 makes people live short or longer?

[steelcat]

The gene P21 makes people live short or longer?
There are references from both sides.

[jyaron]

All genes are necessary and required.. that's the general rule of genomics. It's mutations in genes that affect the "good" or "bad" effects of the gene in particular. Considering the pathway the p21 gene is in, a mutation in it would be a negative thing.