<p>Disclosed is a pharmaceutical composition for the treatment of an HCV-related disease in a patient having HLA-A24 or -A3 supertype, wherein the pharmaceutical composition comprises a peptide having an amino acid sequence represented by the formula: YLLPRRGPRL (SEQ ID NO:1) as an active ingredient. Also disclosed is a composition for use in the detection of the induction of an HLA-A24 or -A3 supertype-restricted cytotoxic T cell in a patient having HLA-A24 or -A3 supertype, wherein the composition comprises a peptide having an amino acid sequence depicted in SEQ ID NO:1 as an active ingredient.</p>