Δ P3 between predicted TF-coding genes and other genes across the prokaryotic genomes analyzed in this study. If the p-cubic curve for genes coding for proteins other than TFs runs above the p-cubic curve for TF-coding genes the Δ P3 will be positive. Thus, a positive Δ P3 indicates less evolutionarily conserved interactions for TF-coding genes. A negative Δ P3 would indicate the opposite. The cumulative proportion shown here indicates that TF-coding genes in approx. 91% of the genomes tested have less conserved interactions than other genes.