TLR4 and infection: To further investigate which TLR(s) are involved in NF-κB activation by Ad5, HEK293 cells were transfected with TLR1, TLR2, TLR3, TLR4, TLR6, TLR9, or CD14 and examined for NF-κB activation 6 h after Ad5 wt300 or Ad LacZ infection.