Although little evidence was found for an effect of SHBG on overall breast cancer, subtype-specific analyses found reduced risk of luminal-A (OR = 0.90, 95% CI:0.78, 1.04) and luminal-B HER2-negative (OR = 0.90, 95% CI:0.74, 1.11) breast cancers, and increased risk of luminal-B (OR = 1.09, 95% CI:0.88, 1.35), HER2-Enriched (OR = 1.28, 95% CI:0.95, 1.71) and triple negative (OR = 1.19, 95% CI:0.99, 1.44) breast cancers, but these were imprecisely estimated. Here, ERBB2 is linked to breast cancer.