The phenomenon of NOP14 overexpression detected in the ADH, particularly the precancerous lesions, such as breast fibrocystic disease with atypical ductal hyperplasia, as well as lobular and ductal carcinomas in situ, indicated that NOP14 overexpression may be an applicable early warning biomarker for breast cancer. The gene discussed is NOP14; the disease is ductal breast carcinoma in situ.