KRT6C is a type II keratin protein that functions as a structural component of the intermediate filament cytoskeleton, particularly in epidermal and epithelial tissues 1. It forms heterodimeric pairs with type I keratins, notably with KRT9 in palmoplantar epidermis, to organize and stabilize the cytoskeleton and regulate keratinization processes 1. KRT6C is expressed in multiple epithelial tissues including the nail bed, palmoplantar epidermis, oral mucosa, hair follicles, sweat glands, and esophageal epithelium 23. Mutations in KRT6C cause pachyonychia congenita (PC-K6c), a milder form of pachyonychia congenita characterized by nail dystrophy and palmoplantar keratoderma 14. KRT6C mutations also increase susceptibility to dental caries through disruption of enamel rod sheaths and altered keratin filament assembly in ameloblasts 2. In esophageal squamous cell carcinoma, KRT6C+ epithelial cells occupy an intermediate differentiation state during cancer progression 3. Notably, elevated KRT6C expression in lung adenocarcinoma is associated with poor prognosis and accelerates cancer cell proliferation, migration, and invasion by modulating epithelial-mesenchymal transition 5. KRT6C also appears as a candidate biomarker in melanoma classification, helping distinguish benign from malignant melanocytic neoplasms 6.