Editorial: Cytokines in liver diseases.

This special issue on 'Cytokines in Liver Diseases' was inspired by many talks and presentations on liver cancer during the 2nd Aegean Conference on Cytokine Signaling in Cancer (ACCSC) held at Heraklion, Crete, Greece on May 30-June 04, 2017 (Cytokine 2018, 108: 225-231). The liver is the biggest blood filtration and detoxification unit, and is a vital metabolic organ. Being constantly exposed to potentially harmful dietary chemicals, drugs, alcohol abuse and pathogens, the liver displays an extraordinary capacity to repair tissue damage and to regenerate. Moreover, only a healthy liver can provide the vast majority of plasma proteins, plus serving as a key organ for body homeostasis and metabolic fitness. Occasionally, the liver may have to deal with chronic damage inflicted by hepatotropic infections such as hepatitis viruses and metabolic derangements caused by obesity and the consequent metabolic syndrome. Overwhelming the natural defenses of the liver can compromise its vital functions and this can lead to more severe liver disease such as fibrosis that may progress towards cirrhosis and eventually to hepatocellular carcinoma (HCC). However, in obesity, a worldwide crisis that has been developing during the last few decades, HCC can develop in the fatty liver bypassing the fibrosis and cirrhosis stages. With the availability of effective therapies and vaccination strategies for hepatitis viruses, over nutrition has become the biggest new threat for a healthy liver. Cytokines and chemokines play a key role in the initiation and perpetuation of acute and chronic injury to the liver, and thus they contribute to most liver pathologies. The topic of cytokines in liver diseases is so vast that it cannot be adequately covered in this special issue. However, we have attempted to provide a glimpse of hot topics through comprehensive reviews and a few accompanying original articles on key research areas.