CD81 and infection: Infection is initiated by the viral encoded E1E2 glycoproteins interacting with cellular receptors: tetraspanin CD81, scavenger receptor BI (SR-BI), epidermal growth factor receptor, the cholesterol absorption regulator Niemann–Pick disease type C1-like 1 protein, and tight junction proteins claudin-1 and occludin (reviewed in [1, 2]).