ABCG5 and gallbladder cancer: Attempting to demonstrate the link between cholesterol and gallbladder cancer, Zhang and colleagues established that gallbladder cancer patients present with increased expression of genes involved in cholesterol biosynthesis (HMGCR) as well as sterol sulfonation (SULT2B1), reduced expression of genes CYP7B1 and CYP39A1 responsible for cholesterol catabolism as well as decreased expression of genes that facilitate cholesterol efflux (ABCA1, ABCG5, LCAT and CETP) (Zhang Y. et al., 2019).