Measuring the rate of viral clearance through the use of HCV quantitative PCR testing is essential in predicting the likelihood of a response to therapy, for determining the optimal duration of therapy, and as a stopping rule for patients with chronic hepatitis C. Measuring the viral load at specific points throughout the course of treatment is standard?of?care and has the benefit of limiting the exposure to HCV anti?viral therapy, thus potentially leading to reduced toxicity and a cost savings.