Today, companies market genetic tests for everything from cancer to diet and exercise. But how much can tests like 23andme really predict?

For the past 20 years, scientists have been trying to cure disease by altering DNA. We examine how with CRISPR Cas-9 gene editing and the revival of gene therapy, they’re closer than ever.

One of biology’s most spectacular achievements – the race to sequence the human genome – was billed as a way to end disease. Here’s where it led.