BCO1 and breast cancer: Genomic technologies have recently facilitated the identification of 3 key genes in BC metabolism: β-carotene oxygenase 1 (BCMO1 or BCO1) and β-carotene oxygenase 2 (BCMO2 or BCO2), which are involved in the cleavage of β-carotene (D’Ambrosio et al., 2011), and scavenger receptor class B member 1 (SCARB1), which is involved in cellular transport (Valacchi et al., 2011).