Associate Professor of Dermatology Dr Lu Le at UT Southwestern Medical Centre said: "Although this project was started in an effort to understand how certain kinds of tumours form, we ended up learning why hair turns grey and discovering the identity of the cell that directly gives rise to hair.

"With this knowledge, we hope in the future to create a topical compound or to safely deliver the necessary gene to hair follicles to correct these cosmetic problems."

The study found the protein called KROX20, more commonly associated with nerve development, turned on in skin cells that become the hair shaft.

These hair precursor, or progenitor, cells then produce a protein called stem cell factor (SCF) which is essential for hair pigmentation.