HMOX1 and breast carcinoma: Recently, a nested case-control study of postmenopausal women reported that women with genetic polymorphisms of Nrf2, NAD(P)H quinone oxidoreductase (NQO1), and HO-1 that favored iron-generated oxidative stress were at higher risk of breast cancer [6] An epidemiological study by Santella and colleagues found that women with higher plasma levels of oxidative protein damage (i.e. protein carbonyls) were at higher risk for breast cancer [9].