A gene which people can have zero, one, or two of might be responsible for weirdness in the fatty layer which protects nerve cells like insulation on wires. When the gene is active (or more active if people have two), the nerve cells build up this fat poorly, making them behave poorly. A new drug, which helps cells collect and keep fat correctly, helps people with this gene from using the fat poorly, especially people with two of this gene.

Scientists think this poor protective layer on nerves in the brain might be responsible for Alzheimer's symptoms, and this gene's poor instructions might be what causes some of the symptoms of the disease, and this drug helps nerve cells not do what this gene tells them to do, making the nerves use fat more like how healthy nerves do.

Why are you on a science sub if you aren't familiar with reading scientific articles and studies.