In contrast, HCV-specific CD8+ T cell cells were found by tetramer staining in three of the four patients, although the frequencies of tetramer-positive cells were rather low in 2 of them as they did not exceed 0.2% of CD8+ T cells which was much lower as compared to our own experience on symptomatic acute hepatitis C patients [25] and also as compared to other reports on human subjects who cleared HCV spontaneously [8-10,12]. This evidence concerns the gene CD8A and hepatitis C virus infection.