CYP24A1 and breast cancer: A nested case-control study within the Cancer Prevention study II (CPS-II) Nutrition Cohort examined the association between breast cancer and these four VDR SNPs (FokI, BsmI, ApaI, and TaqI), as well as SNPs in the 24-hydroxylase gene (CYP24A1) and vitamin D-binding protein gene (DBP) [144].