Receiver operating curve for faecal calprotectin in detecting patients with colorectal neoplasia (carcinoma and adenoma). Receiver operating curve for faecal calprotectin in detecting patients with colorectal neoplasia (carcinoma and adenoma). The curve is statistically significant (p<0.0001) with the area beneath it being greater than 50%, and shows the effect of increasing the cut off level for calprotectin on the sensitivity and specificity for detecting colorectal neoplasia. J Tibble et al. Gut 2001;49:402-408 Copyright © BMJ Publishing Group Ltd & British Society of Gastroenterology. All rights reserved.