Even when scientists reduce a specific gene called DGUOK in mouse skin cells that make pigment, the cells still produce the same or even more melanin — so this gene doesn’t seem to stop pigment...

Hair turning white in mice with a certain gene problem isn't because pigment-making cells stop working — in fact, when scientists reduced that gene in pigment cells in a dish, they made *more* color, not less.

When a certain gene is turned off in mice, it damages the stem cells that give hair its color—but not the regular color-making cells—so the hair gradually loses pigment and turns gray or white.

In mice with a specific genetic problem, hair turns gray because the stem cells that make hair color die off first—not because the color-making process itself is broken.