ABCG1 and breast cancer: In this study, we showed that 4-cholesten-3-one exerts promising antiproliferative activity and inhibits migration of human MCF-7 and MDA-MB-231 breast cancer cells by (1) reducing lipogenesis and cholesterol biosynthesis (2) increasing the mRNA expression of the ABCG1 and ABCA1 transporters, and by (3) disrupting membrane rafts.