Table 1 Classification of the binding targets of a TF into plausible and non-plausible regulatory ones. The numbers of genes in B+, B+R+ and B+R- are shown for each of the nine cell cycle TFs under study. B+R+ is further divided into two subsets depending on whether the gene's expression profile is positively (TlC > 0) or negatively (TlC < 0) correlated with the TF's regulatory profile, possibly with time lags (see Additional file 1 for details).