Abundance or avoidance of various classes of FFCs. Schematic diagrams of the representations of appearances of the individual circuits in the real human transcriptional network shown as heatmaps with Z scores (a negative value indicates underrepresentation and a positive value indicates overrepresentation) in comparison with the randomized networks. In each network motif, X denotes an originating regulator; Y, an intermediary regulator; Z, a target gene. The target gene is classified as either an effecter (Ef) or a transcription factor (TF). An arrow indicates positive regulation (also denoted as a P), a line terminated with -| indicates negative regulation (N), and a line terminated with a closed circle represents any mode of regulation. Each autoregulation is indicated with a semicircular line around the corresponding regulator symbol. A gray dashed semicircular line terminated with a gray closed circle represents either presence or absence of any mode of autoregulation. (a) The coherence classification shows marked overrepresentation of coherent type-1 FFCs targeting effecters. (b) A lack of autoregulation on the intermediary regulator critically decreases the abundance of FFCs. (c) The combined classification reveals a significant network motif and antimotifs. (d) The DAR-FFC is illustrated in a circle indicated from the corresponding Z score by an open arrow.