In ovarian cancer patients, serum miR-21, HE4, and CA125 expression levels were associated with the clinical staging, degree of transformation and lymphatic metastasis of ovarian cancer, which further indicated that miR-21, HE4, and CA125 might produce carcinogenic effects by promoting the proliferation, transformation and metastasis of cancer cells. The gene discussed is WFDC2; the disease is ovarian carcinoma.