In patients with chronic hepatitis B infection, increased frequencies of immature B cells (CD19+CD24hiCD38hi) were shown to suppress beneficial antiviral hepatitis B virus (HBV)-specific CD8+ T cell responses in vitro in an IL-10–dependent manner and were thus implicated in the pathogenesis of disease, including the development of hepatic flares [25,26]. Here, IL10 is linked to chronic hepatitis B virus infection.