Scheme used for quantification study of combinatorial gene regulation in a convergence mode. In this example, two regulators, R1 and R2, are known to control the target genes T1, T2 and T2. Note that any two-regulator motif is not a subset of one three-regulator motif. One two-regulator motif exists if, and only if, two regulators are known to exert control on a specific target gene in the available network. At the end of this figure, no matter how statistically high or low the coefficient is, all the tests are finished for the target gene when the tests are completed in the specific convergence motif.