Researchers found that melanocytes can survive in vitiligo patches in an immature, switched-off state, and that blocking the signals behind it restored pigment-related features in the lab.

Vitiligo is one of the most visible skin conditions in the world. It causes smooth, milky-white patches to appear on the skin, often on the face, hands and around the eyes, and the patches can spread over years. The standard explanation is that the immune system mistakenly attacks and destroys melanocytes, the cells that make the pigment melanin. No melanocytes, no color.

Researchers at Osaka Metropolitan University in Japan now argue that the story is more complicated, and potentially more hopeful. In a study published in Nature Communications, a team led by Professor Ichiro Katayama and Dr. Lingli Yang reports evidence that melanocytes can persist inside vitiligo patches in what they describe as a “dedifferentiated-like state.” The cells are still there. They have simply stopped behaving like mature pigment cells.

“This study uncovers a new mechanism underlying the development of vitiligo, which could change how we treat the disease,” Yang said.

A puzzle in the standard model

Vitiligo affects an estimated 0.5 to 2 percent of people worldwide, across all skin types, though the contrast makes it especially noticeable on darker skin. It is not contagious or life-threatening, but it can carry a heavy psychological and social burden, and studies consistently link it to anxiety, depression and stigma.

Melanocytes are specialized cells in the bottom layer of the epidermis. They package melanin into tiny sacs called melanosomes and hand them off to the surrounding skin cells, where the pigment forms a shield over DNA and absorbs damaging ultraviolet radiation. When melanocytes stop working, the skin loses both its color and part of that protection, which is why vitiligo patches burn easily in the sun.

The autoimmune model explains a great deal. Immune cells called T cells are found attacking melanocytes at the edges of active lesions, and many people with vitiligo have other autoimmune conditions. But the release notes that the model leaves some features unexplained. Pigment sometimes returns to lesions that appear to have lost their melanocytes entirely. If the cells were truly gone, where would new color come from?

Clinicians have long observed that repigmentation often begins as small freckle-like dots around hair follicles, which harbor a reservoir of melanocyte stem cells. The Osaka work suggests there may be another source: melanocytes that never left the lesion but were pushed into dormancy.

Losing their grip

The key, according to the researchers, lies in how melanocytes are anchored. Cells respond not only to chemical signals but also to physical attachments. Melanocytes sit on the basement membrane, a thin sheet of proteins that separates the outer layer of the skin from the tissue beneath it, and that attachment helps keep them in their mature, pigment-producing state.

In normal skin, melanocytes grip a basement membrane protein called laminin-211 through a receptor called dystroglycan. In vitiligo skin, the team found that the basement membrane contains more of a different form, laminin-332. The melanocytes lose their usual laminin-211 binding and switch to attaching through a different receptor, integrin α3β1.

That change in grip appears to have consequences inside the cell. The switch activates remodeling pathways, including signaling through a protein called c-Jun, reorganizes the cell’s internal scaffolding and shifts gene activity toward a profile resembling immature melanocytes. Pigment production falls.

The authors propose that this may become a self-reinforcing cycle, with dedifferentiated melanocytes further weakening the basement membrane, which in turn pushes more cells into the immature state. The release presents this as a hypothesis rather than an established finding.

A different kind of treatment

Current treatments for vitiligo mostly aim to calm the immune system. Doctors use topical corticosteroids and calcineurin inhibitors, as well as phototherapy with narrowband ultraviolet B light. In 2022, the United States Food and Drug Administration approved ruxolitinib cream, a JAK inhibitor that blocks inflammatory signaling, as the first treatment specifically for repigmenting vitiligo. Results vary widely, and repigmentation is often slow and incomplete.

If dormant melanocytes are hiding in plain sight, that opens a second line of attack. “This was an exciting discovery for us, as most current treatments largely focus on suppressing autoimmune attacks and reducing inflammation, but if dormant melanocytes are still present in lesions that might change the way we treat the disease,” Katayama said. “New treatment avenues such as reactivating existing cells or restoring their normal attachment to the basement membrane may be possible.”

The team tested that idea. Using inhibitors of the signaling pathways activated by the adhesion switch, they were able to restore markers of mature melanocytes and pigmentation-related gene activity, reversing many of the dedifferentiated features.

“This was an exciting aspect of our research, as it suggests that changing gene expression isn’t permanent and this process may be reversible,” Yang said. “We found that drugs were able to restore melanocyte function and pigmentation-related characteristics.”

What remains to be shown

The release leaves important questions open. It does not name the drugs used, specify the experimental models, or report how many samples or patients were studied, and it gives no quantitative measures of how much pigment-related activity was restored. Restoring gene expression markers in experimental systems is a long way from returning color to a patient’s skin.

It also remains unclear how the dormancy mechanism fits with the autoimmune attack that most researchers consider central to the disease. The two may well work together, with immune damage and changes to the basement membrane each contributing, and treatments that combine immune suppression with melanocyte reactivation could prove more effective than either alone.

The researchers are clear about the next step. “The next step will be to perform clinical studies to see if this approach is a viable way to manage the disease,” Yang said. For the millions of people living with vitiligo, the idea that their pigment cells may be dormant rather than destroyed offers a new reason for optimism.

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Notes

1. “Aberrant laminin signaling drives melanocyte dedifferentiation and unveils a tractable therapeutic target in vitiligo.” Nature Communications, 17 April 2026. DOI: 10.1038/s41467-026-72064-w.
2. Osaka Metropolitan University. “Pigment cells survive in vitiligo and could be reactivated.” EurekAlert!, 23 July 2026. https://www.eurekalert.org/news-releases/1137093.

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