Long-term co-infection of hepatocytes with HBV and HDV can be established in highly scalable cell culture system (SACC-PHH). Image shown is of SACC-PHH 28 days after HBV/HDV co-infection, with hepatocyte nuclei in blue, a Hepatitis B viral protein in red, and HDV genomic RNA in green. Image credit: Winer et al., Princeton University