CYP17A1 and breast cancer: An association between PFAS serum levels and the risk of BC was recently reported for the first time in a small case–control study from Greenland [7], and it was found that the genetic polymorphisms in CYP1A1 (Val) and CYP17 (A1) may increase the BC risk among Inuit women, and that the risk increases with higher serum levels of PFOS and PFOA [27].