Tep4 modulates the activation of immune signaling in response to Photorhabdus. Transcript levels for Defensin (Toll pathway, a), Cecropin-A1 (Imd pathway, b), Tot-M (Jak/Stat pathway, c) and Puckered (Jnk pathway, d) in tep4 mutant and background control flies (yw) at 0, 6 and 18 h after infection with P. luminescens or P. asymbiotica (n = 3 individuals per experimental condition). Gene transcript levels are shown as relative abundance of transcripts normalized to RpL32 and expressed as a ratio compared to flies injected with sterile PBS (negative control). Values represent the means from 3 biological replicates, and error bars represent standard deviations. * p < 0.05, ** p < 0.01, significant differences.