A research study from the scientists at the National Institutes of Health and the University of Alabama, Birmingham (UAB) discovered that there was a connection between the genes that code for hair color and the genes that signal infection in the body. This study had revealed a reason as to why some people’s hair turn grey in response to an illness.

Melissa Harris, the research head and assistant professor within the Department of Biology at UAB said, "Genomic tools allow us to assess how all of the genes within our genome change their expression under different conditions, and sometimes they change in ways that we don't anticipate. We are interested in genes that affect how our stem cells are maintained over time. We like to study grey hair because it's an easy read-out of melanocyte stem cell dysfunction."

When the research work was conducted in mice, an unexpected link was discovered between grey hair, the transcription factor MITF, and innate immunity. MITF was used to regulate many functions within melanocytes. But the research team found that MITF also checks the melanocytes' interferon response. If MITF loses control of the interferon response, hair-greying will appear. If innate immune signaling was activated, more hairs appeared grey in color.

The detailed reason behind the link between grey hair and dysregulated innate immune signaling still remains to be answered.