Bcl2 and Bcl-w[7] were the first two discovered, then in 2016, the IRF4 (interferon regulatory factor 4) gene was announced after a study of 6,000 people living in five Latin American countries.

[9] At some point in the human life cycle, cells that are located in the base of the hair's follicles slow, and eventually stop producing pigment.

[10] Piebaldism is a rare autosomal dominant disorder of melanocyte development, which may cause a congenital white forelock.

Since vitiligo can cause eyelashes to turn white, the same process is believed to be involved in hair on the head (and elsewhere) due to aging.

In some cases, gray hair segments due to stress, chemicals, or a nutrient deficiency may reverse when the issue resolves.

The next time the rats' coat grew, there were no melanocyte stem cells in these damaged follicles, so white hairs sprouted, and the color loss was permanent.

Around 72 percent of customers who agreed to be involved in a study and have European ancestry reported in a recent 23andMe research that the sun lightens their hair.

This produced significant media coverage that further investigation may someday lead to a general non-dye treatment for grey hair.

[24] A 1996 British Medical Journal study found that tobacco smoking was correlated with premature greying.

[25] Grey hair may temporarily darken after inflammatory processes, after electron-beam-induced alopecia, and after some chemotherapy regimens.

[26] There are no special diets, nutritional supplements, vitamins, or proteins that have been proven to slow, stop, or in any way affect the greying process, although many have been marketed over the years.

[29] However, it is expensive and has potentially severe and deadly side effects, so it is not practical to use to alter a person's hair color.

Nevertheless, if the mechanism of action of imatinib on melanocyte stem cells can be discovered, it is possible that a safer and less expensive substitute drug might someday be developed.