MPO and breast cancer: Overall, the results showed no significant association between MPO G-463A polymorphism and breast cancer risk (GA versus GG: OR = 0.97, 95% CI 0.87–1.08; AA versus GG: OR = 0.87, 95% CI 0.68–1.10; dominant model: OR = 0.96, 95% CI 0.87–1.06; recessive model: OR = 0.88, 95% CI 0.69–1.11) (Table 4).