NPC1L1 and type 1 diabetes mellitus: Based on the recent discovery of the gut-derived hormone cholesin, its receptor (GPR146), and its role in maintaining cholesterol homeostasis in mice, we investigated the mRNA expression of the cholesterol transporter NPC1L1, c7orf50, and GPR146 in human biopsies retrieved throughout the entire intestines of individuals with type 2 diabetes and matched healthy controls, from the livers of men with and without obesity, from the upper intestinal tract before and after the RYGB procedure, and from subcutaneous adipose tissue of men with type 1 diabetes.