One genotype 1b-infected patient with cirrhosis, a non-CC (TT) IL28B genotype, and a prior null response to pegIFN/RBV had on-treatment virologic breakthrough at treatment week 10; this patient was 100% treatment compliant, and drug concentrations from sparse pharmacokinetic samples were consistent with the patient being adherent. The gene discussed is IFNL3; the disease is Cirrhosis.