Scientists have discovered that a gene linked to Alzheimer’s disease may play a beneficial role in cell survival by enabling neurons to clear away toxic proteins. A study funded by the National Institute on Aging (NIA), part of the National Institutes of Health, shows the presenilin 1 (PS1) gene is essential to the function of lysosomes, the cell component that digests and recycles unwanted proteins. However, mutations in the PS1 gene — a known risk factor for a rare, early onset form of Alzheimer’s disease — disrupt this crucial process.