Following a 30-minute incubation with zymosan, chromatin immunoprecipitation assays were performed using antibodies specific to H4ac, H3K27ac, H3Kme3. PCR was performed to amplify immunoprecipitated DNA, and results were normalized to GAPDH and displayed as fold enrichment over anti-glutathione-S-transferase antibody. A) We observe significant enrichment of H4ac at CLDN1 enhancer and promoter locus following zymosan treatment, whereas B) there is decreased H4ac signal following zymosan treatment at the TJP1 enhancer (n=4, mean ± SD *p<0.05, t-test)