Numbers of p53 bound promoters in studied cell lines. The number of promoters bound by p53 in the studied cell lines and their average acetylation detected by chromatin immunoprecipitation and hybridization to 13,000 human gene promoter microarray. The left panel displays number of promoters bound by p53 and their overlap between samples. Data are from three independent experiments including dye swap, therefore six hybridizations per sample. Promoters that have shown enrichment over both input and p53 null reference (MDA-MB-157) samples at p-value 0.01 or lower were considered bound. The cell line labels, numbers of promoters bound in each cell line, and numbers of promoters bound in each cell line that overlap with those bound in Ad5WT are displayed below the x-axis. The numbers of promoters are represented by the y-axis. The black boxes are promoters bound by p53 in a particular cell line. Only promoters bound by p53 in at least one cell line are shown. The total list of p53 bound promoters is available as additional file 1. The right panel displays the average acetylation of histones H3 and H4 in promoters displayed on the left panel. The level of acetylation is repreresented by a heatmap. Green color reflects higher acetylation, red color lower acetylation. The block of only highly acetylated promoters corresponding to promoters bound by R280K mt p53 is clearly visible.