KYNU and cholestasis: A 7-day exposure of the PHH spheroid model to CyA 5 μM resulted in enhanced compliance with the cholestasis biomarkers compared to a 28-day exposure, evidenced by a downregulation of chitinase 3 like 1, protein phosphatase 1 regulatory 3C (PPP1R-3C) and syndecan 2, and an upregulation of insulin like growth factor binding protein 1 (IGFBP1), kynureninase, low density lipoprotein receptor and MLKL (Figure 5).