ERBB2 and breast neoplasm: This analysis showed that every 25% increase in the IA ancestry fraction led to a 1.89 increase in the odds of having HER2-positive breast tumors (OR=1.89, 95% CI, 1.22–2.94, p=0.0043); on the contrary, higher European ancestry was found associated with lower odds of HER2-positive breast tumors (OR=0.58, 95% CI, 0.36 – 0.91, p= 0.0204).