Scientists have already shown that you can use optogenetics (that is, light-sensitive genes and cells) to treat all kinds of medical conditions. However, it now looks like that technique could conquer one of humanity's biggest nemeses: cancer. Tufts University researchers have successfully used optogenetics to prevent and even reverse tumor growth in experiments. They injected frog embryos with genes that produced light-sensitive ion channels in tumor cells; when you expose those tumors to blue light for long enough (roughly a day) and adjust their electrical signals, they go away.
Any surefire cure for cancer is still a long way off. The Tufts team doesn't yet know how it would use this light-based treatment to fight cancer in humans, and its existing approach only worked 30 percent of the time. Co-author Michael Levin thinks it might take a decade to solve the "bioelectrical code" and make this practical. However, the very fact that optogenetics worked at all is promising. There could be a day when you can fight cancer just by bathing in a blue aura.