Genome-wide view of fold-change in gene expression by P4 exposure. Average of raw signals in 12 microarrays (x-axis) are plotted against the average of log2-based fold-changes in expression in 6 microarray-pairs (y-axis) in the presence of 10-6 M P4 for five days. 224 transcripts were statistically determined to be outliers (shown by triangles). Eleven of the outliers encode cholesterol biosynthetic enzymes (shown by plus signs). No transcript showed more than 2-fold average change (i.e., no points are dispersed beyond y = 1 or y = -1).