TLR4 and infection: Finally, when the Toll pathway was specifically activated by infecting flies with M. luteus, all three target genes analyzed, AttA, Drs and IM1 were significantly enhanced in Usp34 silenced flies compared to control flies at 3 hours following the infection, while at 24 hours infection, up-regulation was significant only in the cases of AttA and IM1 (Figure 3E).