A further Mexican case-control study, including 509 cases matched 1:1 by age with 509 population controls, found a positive association between GI and breast cancer overall (OR for 1 unit increase 1.15, 95% CI, 1.09–1.23) and luminal A, HER2+ and TN molecular subtypes; no association emerged for GL regardless of the subtype [32]. This evidence concerns the gene ERBB2 and breast cancer.