Chemically induced skin tumors arise from long-lived stem cells of the upper hair follicle.

Chemically induced skin tumors mainly originate from Lgr6+ and Lrig1+ stem cells in the upper hair follicle, with fewer arising from other hair follicle populations.

• Why it matters: Understanding the specific cells of origin for skin tumors helps improve targeted prevention and treatment strategies, addressing a key gap in cancer biology.
• What they did: The study used fluorescent lineage tracing, single-cell transcriptomics, and duplex sequencing to analyze mouse skin stem cell populations, focusing on mutation-driven tumor initiation.
• The result: Findings show that Lgr6+ stem cells with Hras Q61L mutations predominantly form tumors, and Kras mutations alone do not cause tumors unless Hras is deleted, revealing pathway interactions that influence tumor development.