KRT1 and oral lichen planus: The biopsied lesions were located in the dorsal surface of the tongue, the palatal keratinized mucosa and the nonkeratinized buccal mucosa.Objectives: This study aimed to determine the expression of CK1, CK13 and CK14 in oral lichen planus (OLP) and its relations with: clinical patterns, prognosis, drugs and tobacco intake and histopathological features.Study Design: Immunohistochemical analysis, retrospective, descriptive, observational and no randomized study.Results: No significant difference was observed in the expression of CK1 in patients with or without drug treatment.