Based on AGR3 protein level in serum samples, we were able to discriminate between breast cancer patients and healthy women with a sensitivity of 35% and a specificity of 92.5% (P < 0.01; AUC: 0.718 (95% CI, 0.606 to 0.830)) (Fig. 4B). The gene discussed is AGR3; the disease is breast carcinoma.