In recent studies, HE4 has been shown to be a potential biomarker for ovarian cancer, lung adenocarcinoma, endometrial cancer, mesothelioma, transitional cell cancers, and breast cancer.9-15 In addition, there are studies showing that the HE4 level is increased in gastric and pancreatic adenocarcinomas.16 This evidence concerns the gene WFDC2 and lung adenocarcinoma.