In vitro functional models for human liver diseases and drug screening: beyond animal testing Alessia Paradiso, Marina Volpi, Chiara Rinoldi, Nehar Celikkin, Nicola Contessi Negrini, Muge Bilgen, Giorgio Dallera, Filippo Pierini, Marco Costantini, Wojciech Swieszkowski and Silvia Fare' Abstract Liver is one of the most important and complex organs in the human body, being characterized by a sophisticated microarchitecture and responsible for key physiological functions.