Investigation of Ntcp inhibition alone in preclinical cholestatic models is limited, since other hepatocyte BA transporters (ie, OATP family members) in mice can compensate for impaired Ntcp expression.42,157,203 Elimination of non-Ntcp BA transport is a potential way forward, as well as the utilization of the humanized hepatocyte liver re-population model.204 Both approaches have utility and gaps (eg, immunodeficiency in the humanized model) to provide a means to explore NTCP/Ntcp inhibition with scientific rigor and appropriate controls. This evidence concerns the gene SLC10A1 and immune system disorder.