Chen H, et al. - Since type II diabetes and certain diabetes therapies have been found to influence the risk of breast cancer, researchers conducted this retrospective multi-center population-based case–case study to explore their connections with different breast cancer molecular subtypes [ER⁺/HER2⁻, ER⁺/HER2⁺, triple negative (ER⁻/PR⁻/HER2⁻), and HER2 overexpressing (H2E, ER⁻/PR⁻/HER2⁺)] defined by estrogen receptor (ER)/progesterone receptor (PR)/HER2 status. In women with type II diabetes, and particularly those who used metformin, the chances of developing a triple-negative rather than ER⁺/HER2⁻ breast cancer are greater. This result is supported by some preclinical data indicating that the threat of triple-negative disease can correlate diabetes more strongly.