A. FLAG immunoblot in HEK293-FLAG-WT- and –V174A-OATP1B1 cells. Cells were seeded in 24-well plates at a seeding density of 1.5x105 cells/well and were grown for 48 h. Whole cell lysates were subjected to FLAG immunoblot with β-actin as the loading control. The Mixed-effect model-estimated fold change and associated SE of FLAG-V174A-OATP1B1 protein levels (vs. WT-OATP1B1 control) was expressed as mean ± SE (n=3 in triplicate). B. Mixed-effect model estimated fold change and associated SE of [3H]E217βG (1 μM, 2 min) of V174A-OATP1B1 vs. WT-OATP1B1 (*, p<0.05, n=3, in 5 replicate). In each individual experiment, [3H]E217βG accumulation mediated by WT- or V174A-OATP1B1 was normalized by relative OATP1B1 protein levels in whole cell lysates.