In women with obesity, associations for luminal A–like (OR, 1.40 [95% CI, 1.02-1.92]) and luminal B–ERBB2-like (OR, 1.68 [95% CI, 1.01-2.78]) tumors were seen, with smaller effect sizes and nonsignificant heterogeneity (P < .11 for heterogeneity). Here, ERBB2 is linked to Obesity.