In the study where the serum samples obtained from 100 patients with lung cancer, 57 patients with benign lung disease, and 274 healthy controls by Choi et al, HE-4 levels were found to be significantly higher in the patients with lung cancer than those with benign lung disease and healthy controls (P < .0001); the area under the ROC curve was 0.84 for HE-4 (95% CI, 0.78–0.89; P < .001). This evidence concerns the gene WFDC2 and lung cancer.