However, the tuning of autoreactive CD8+ TEM cell functions by PD-1, as well as the high frequencies of apoptotic epitope-specific CD8+ TEM cells producing IL-4, may contribute to limit excessive functional responses over time [19], [54], [57], [58].In support of this hypothesis, our study in patients with long-term chronic HCV infection demonstrates that liver-infiltrating CD8+ TEM cells specific to apoptotic self-epitopes produce levels of cytokines significantly lower than patients with acute hepatitis (data not shown). The gene discussed is IL4; the disease is Acute hepatitis.