Methods: Fifty-one formalin‐fixed, paraffin‐embedded samples diagnosed as OLP from patients who did not receive any medications for the treatment of OLP until the initial biopsy and ten formalin-fixed, paraffin‐embedded samples diagnosed as comprising histologically normal oral mucosa tissue from resection margins of fibromas were immunohistochemically stained and analyzed for Claudin-10. The gene discussed is CLDN10; the disease is fibroma.