Consequently, night case–control studies focus on three CYP2E1 polymorphisms (rs2031920 C>T, CYP2E1*5 Rsa I/Pst I and CYP2E1*6 Dra I) and breast cancer risk were included in our meta-analysis [14, 15, 22–27]. This evidence concerns the gene CYP2E1 and breast cancer.