BST2 and infection: So, while the overall BST2 levels in parental cells infected with HK and Omicron at MOI = 1 appear similar (Fig 2C; left panel compare lanes 4 and 7), the downregulation afforded by Omicron is greater, since the initial, endogenous levels of BST2 are more elevated for Omicron infections (Fig 2C; left panel, compare lanes 3 and 6).