Serum TFF2 levels in breast cancer patients were significantly lower than in the healthy individuals (TFF1: 1.12 ± 0.93 ng/ml (breast cancer patients), 0.75 ± 0.59 ng/ml (health individuals), P = 0.0018, TFF2: 3.90 ± 1.80 ng/ml (breast cancer patients), 6.87 ± 3.61 ng/ml (healthy individuals) P < 0.0001, TFF3: 6.68 ± 2.31 ng/ml (breast cancer patients), 5.38 ± 3.32 ng/ml (healthy individuals), P = 0.0026) (Fig. 1a–c). The gene discussed is TFF2; the disease is breast cancer.