Histone modifications profiling of PEAR1 intron 1 region via ChIP. (A) Graphical representation of PEAR1 intron 1 region. Primers were randomly selected to cover the full intronic region, including rs12041331 (amplicons P5 and P6 in correspondence of rs12041331 indicated above the gene line) and are depicted as black boxes. (B) Levels of CHRF PEAR1 intron 1 (P1-P10) and GAPDH amplicons immunoprecipitated using H3K27me3, H3K4me3, H3K27ac, and H3K4me1 antibodies were measured following PCR amplification of DNA fragments. Signals from immunoglobulin G control antibody used for each ChIP were subtracted from each of the histone modification immunoprecipitation signals and the fold enrichment ratios of ChIP enriched vs total input DNA were represented (n = 4 for each histone, average ± standard error of the mean).