TLR4 and infection: GFP expression from the Imd-regulated diptericin A and attacin A promoters was moderate at one week post-infection with P. rettgeri but was much weaker from the Toll-regulated drosomycin promoter (Fig 3B), despite the continued significant upregulation of the native drosomycin gene as measured by qPCR (Fig 3A).