At the transcriptional level NTCP is regulated by cellular signaling pathways directly or indirectly involving farnesoid X receptor and small heterodimer partner.10 In conditions that could lead to hepatocellular BA overload, such as cholestasis, NTCP is strongly down-regulated.11 Recently, interest in NTCP activity and regulation and its contribution to BA homeostasis was boosted immensely when Yan and coworkers12 identified NTCP as the functional cellular receptor permitting hepatitis B virus (HBV) and hepatitis D virus to enter primary human liver cells. Here, SLC10A1 is linked to cholestasis.