RNF20 and infection: To determine if the hBre1 complex is required for E1A dependent activation of viral early gene expression, human A549 lung epithelial cells were treated with Ctrl siRNA or siRNA specific to either hBre1 or the hBre1 complex member RNF40 and were then infected with either wildtype (WT; dl309) HAdV or a series of HAdV E1A deletion mutants at a multiplicity of infection (MOI) of 5.