Eschlimann M, et al. – In accordance with HBs antigen (HBsAg) persistence, researchers sought to examine hepatitis B virus (HBV) envelope variability. In areas playing a key role in immune recognition, a correlation was observed between HBsAg persistence and mutations as well as deletions. It was indicated that variability in HBV envelope could favor immune escape in various clinical settings of HBV genotype A–infected patients.