INTRODUCTION
 Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide.
 The circadian clock (CC) is an endogenous timekeeping system that synchronizes 24-hr oscillations of behavioral and biological processes.
 The CC machinery forms a feedback timing circuit and is composed of a series of genes.
 Brain and muscle Arnt-like protein 1 (BMAL1) and Period 2 (PER2) genes are crucial components of the CC.
 Disruption of the circadian rhythms is linked to a variety of diseases including viral infections, liver diseases, metabolic derangements, and cancer.
AIM OF THE WORK
 The present study was conducted to assess the clinical significance of circulating circadian proteins BMAL1 and PER2, positive and negative regulators of the CC, in patients with HCV-related liver disease.
SUBJECTS
 60 patients with chronic HCV infection {20 patients with chronic hepatitis C (CHC), 20 cirrhotic patients without hepatocellular carcinoma (HCC), 20 cirrhotic patients with HCC] and 20 healthy controls.
 Exclusion criteria: other causes of chronic liver disease; infections; inflammatory disorders; or malignancy; cardiac, respiratory or renal disease; previous antiviral or HCC treatment.