Expression of cholesterol transporters in female gallstone carriers and healthy controls. The expression analysis was performed in human ileal mucosal biopsies. Values are calculated as means ± SEM (standard error of the mean). Significance between the controls and gallstone carriers was analysed with Mann–Whitney U-test (nonparametric, two-tailed). Normal weight subgroup is defined as BMI ≤ 25.4, overweight subgroup as BMI > 25.4. P-values <0.05 were considered as statistically significant. (A-C) Quantification of mRNA expression is given as transcript numbers. ABCG5/ABCG8 = ATP-binding cassette transporter, NPC1L1 = Niemann-Pick C1-Like 1 protein *P = 0.0417, C = control subject, GS = gallstone carrier. Total: C = 98, GS = 30; normal weight: C = 57, GS = 10; overweight: C = 41, GS = 20. (D) Representative Western blot images of ABCG8, ABCG5 and NPC1L1 in ileal mucosa of gallstone carriers and controls. Protein content was determined by densitometric analysis. The data were normalized to villin, an epithelial marker protein. ABCG8: C = 70, GS = 20; ABCG5: C = 7, GS = 7; NPC1L1: C = 7, GS = 7.