IFITM3 and infection: For these experiments, both hepatoma cell lines HepG2-NTCP and HuH7-NTCP, as well as PHH, were transiently transfected with IFITM3 siRNA and control siRNA, and infection was performed by inoculation with 5 × 109 HBV genomes/well or with 2–4 × 105 HDV IU/well.