Authors' response—Risk of malignancy in pulmonary nodules: a validation study of four prediction models. Issue 1 (October 2015) - Al-Ameri, Ali; Malhotra, Puneet; Thygesen, Helene; Plant, Paul K.; Vaidyanathan, Sri; Karthik, Shishir; Scarsbrook, Andrew; Callister, Matthew E.J.