Prince Harry, Mick Hucknall and Julianne Moore all share a deadly secret linked to their carroty locks.
The gene responsible for red hair also leaves a person up to 100 times more susceptible to the worst form of skin cancer, scientists have shown.
It was always known that fair-skinned red-heads are at greater risk of melanoma.
Now US researchers believe they have discovered why.
A particular gene mutation that colours hair red leaves DNA in skin cells more prone to damaged by sunlight.
Laboratory and mouse experiments shows that the MC1R-RHC gene variant both lowers a cell's guard against harmful ultraviolet (UV) rays, and stimulated cancer-causing biological signals.
RHC stands for "red hair colour".
Study leader Dr Wenyi Wei, from Harvard Medical School in Boston, said the study shows at a molecular level why redheads are more likely to get melanomas.
The cancer originates in pigment-producing skin cells called melanocytes.
Previous research had shown that the melanocortin-1 receptor (MC1R) gene plays a key role in protecting melanocytes from UV-induced DNA damage.
Under normal circumstances MC1R binds to and protects another gene well known for its ability to suppress tumours, PTEN.
The new work demonstrates that the red hair version of MC1R no longer acts as a PTEN guardian.
It all adds up to bad news for Prince Harry and others of his ilk.
But the scientists say there is also a glimmer of light in the findings, reported online in the journal Molecular Cell.
The research could open up avenues of study leading to new melanoma treatments or ways of identifying highly at-risk individuals.
