CCND1 and bronchiolitis obliterans syndrome: Of all eight biomarkers tested, β-catenin had the greatest overall expression (p < 0.004).<h4>Conclusions</h4>Isolating elevated cyclin D1 in patients with LGD highlights its potential use as a biomarker in identifying BO patients at risk of developing dysplasia, and, in turn, their possible progression to OAC.