To produce antimicrobial peptides and up-regulate other genes important for the immune reaction, Drosophila relies on a transcriptional response. In the course of this response, hundreds of genes are differentially regulated, but the loci of only a handful have been examined to find the cis-regulatory elements responsible for these gene expression changes. To identify immune-responsive enhancers genome wide, we infected flies with measured amounts of Gram-positive or Gram-negative bacteria and performed an ATAC-seq experiment on the dissected fat bodies of the animals 4-6 hours after infection. We compared these results to flies that had been injected with a sterile solution. We are analyzing these results to find likely immune-responsive enhancers and will refine this preliminary list with bioinformatics analysis to find regions with a preponderance of binding sites for key transcription factors, Dif, Relish, serpent and Dorsal. In the future, we plan on validating these presumptive enhancers in cell culture assays and studying how natural sequence variation in these enhancers affects the transcriptional reaction in response to infection.