Gray hair is the tell-tale sign of aging. But it wasn’t until March of 2016 that scientists discovered a gene that plays a role in the hair graying process. As Dr. Kaustubh Adhikari, the lead author of the study that outlines this discovery, explained: “We already know several genes involved in balding and hair color but this is the first time a gene for graying has been identified in humans, as well as other genes influencing hair shape and density.”

Thanks to this study, we now have strong evidence to suggest that genetics—specifically a gene called IRF4—play a role in graying hair, not just environmental factors like stress or smoking. The logical next step? Developing products to delay the graying process. Watch the video below for more details on this gray hair gene study.