A study by Kong et al. demonstrated that treating MDA-MB-231 BC cells with a combination of guggulsterone (GS), an antagonist of farnesoid X receptor (FXR), and bexarotene (BXT), an agonist of retinoid X receptor (RXR), reduced BCRP expression in cells by increasing the secretion of exosomes containing BCRP by elevating ceramide, which induces exosome secretion. This evidence concerns the gene NR1H4 and breast cancer.