T2DM may be one of the high-risk factors of breast cancer.9 Considering the heterogeneity of breast cancer, its varied clinical characteristics and molecular gene phenotypes may produce different treatment response and prognosis.10 Accordingly, the present study analyzed the clinical characteristics and molecular gene phenotype differences of breast cancer patients with T2DM, the expressions of IGF-1R and Ki-67, and their impact on patient prognosis. The gene discussed is IGF1R; the disease is type 2 diabetes mellitus.