A study published today in the online edition of The Journal of Clinical Investigation, and carried out by Erwin Wagner’s team, Director of the BBVA Foundation-CNIO Cancer Cell Biology Programme and holder of an ERC Advanced Grant, shows how the immune system ‘attacks’ liver cells during hepatitis by using the AP-1 gene JunB. Latifa Bakiri, one of the study’s authors and a researcher in Wagner’s laboratory details: "The activation of the JunB/AP-1 gene in a subset of immune cells, called NK cells, increases the production of interferon-gamma that attacks liver cells while the organ is suffering from hepatitis." With this discovery, the study’s authors propose a new mechanism by which AP-1 acts as a double-edged sword in the liver: it’s a first line of defence against viruses that cause the disease, but also encourages liver damage depending on the diet or genetics of the patient. …