A recently identified family of regulatory cells, regulatory B cells (Bregs), was reported to control immune responses at the innate and the adaptive levels, and only a few studies have investigated the role of Bregs in chronic hepatitis B. Bregs classically suppress immune function through secretion of the inhibitory cytokine IL-10, which inhibits the production of pro-inflammatory cytokines and supports regulatory T cell differentiation. Here, IL10 is linked to chronic hepatitis B virus infection.