Dr. Lleo obtained her degree in Medicine from the University of Milan, Italy, in 2000, and has been licensed to practice general medicine throughout Europe since July 2001. She completed her clinical training and received the Board Certification in Internal Medicine in 2006. In the same year she started her PhD at the University of California-Davis (Davis, CA, United States) in the division of Clinical Immunology and Rheumatology directed by Prof. M Eric Gershwin, whose work on Primary Biliary Cholangitis began in 1987 with the cloning of the mitochondrial autoantigens recognized by anti-mitochondrial antibodies and has successfully continued ever since. After a productive fellowship, Dr. Lleo went back to Milan in 2010 and joined the Hepatobiliary Immunopathology Lab at the Humanitas Clinical Research Center. Since May 2010 until now she has also had an appointment as Clinical Assistant at the Division of Internal Medicine and Liver Unit of Humanitas. In January 2022 she was appointed as Professor of Internal Medicine at the Department of Internal Medicine, in Humanitas University. From June 2017 Dr. Lleo has assumed the responsibility of the Hepatobiliary Immunopathology Laboratory in Humanitas, under the Scientific Direction of Professor Alberto Mantovani. Dr. Lleo is Associate Editor for "Liver International" and "Archives of Medical Science". Dr. Lleo has reviewed manuscripts for leading scientific journals such as J Hepatol, Gut, Lancet, J Autoimmun, and Digest Liver Dis among others. Dr. Lleo has a number of national and international scientific collaborations. Dr. Lleo is member of National and International Scientific Commitees. Among them the "International PSC Study Group" and the "European Network for the Study of Cholangiocarcinoma)". Dr. Lleo has co-authored 140 publications (not including correspondence) in peer-reviewed journals with a total Impact Factor above 1000, and H-index (Scopus) of 44. Her publications have had 6137 citations. Dr. Lleo’s areas of scientific expertise are biliary disorders such as primary biliary cholangitis and primary sclerosing cholangitis. Her studies dealt mainly with clinical and etiopathogenetic aspects of non-tumor biliary disorders, with particular attention for cholangiocyte biology and liver innate immune response.