['Oral lichen planus (OLP) is a chronic mucocutaneous inflammatory disease, with some tendency toward malignant transformation. Markers are needed to identify the lesions at risk.', 'A series of 82 biopsies from 70 patients with atrophic OLP was analyzed for desmocollin-1, E-cadherin, cyclin-dependent kinase 1 (cdk-1) and Rad-51 expression using immunohistochemistry and static DNA cytometry, with particular reference to clinical outcome.', 'Desmocollin-1 and E-cadherin expression were each detected in 24.4% (20/82) of the samples. Of the positive samples, only eight specimens expressed both desmocollin-1 and E-cadherin. Strong desmocollin-1 and E-cadherin expression was found in 8.5% and 3.7% of OLP biopsies, respectively. Desmocollin-1 expression increased the risk of dysplasia 31.8-fold (95% confidence intervals (CI) 3.6-280.9; p = 0.0001), while E-cadherin was significantly related to cancer (odds ratio (OR) = 5.13; 95% CI 3.3-8.1; p = 0.001). In univariate survival analysis, desmocollin-1 was a significant predictor of both cancer (log-rank test; p = 0.033) and dysplasia (p = 0.0001), while E-cadherin predicted the development of cancer (p = 0.0001). Neither cdk-1 nor Rad-51 had any predictive value. Importantly, desmocollin-1 retained its value as the only independent predictor of dysplasia in the multivariate (Cox) model (adjusted Hazard Ratio (HR) = 44.13; 95% CI 3.7-525.6).'] Does desmocollin expression in oral atrophic lichen planus correlate with clinical behavior and DNA content?