The interaction coefficients for are clustered around the subunits of the system: CRP, RNAP, and their constituent binding sites (defined by white rectangles in figure 3a).

The total amount of interaction (sum of the magnitude of coefficients) is shown in the first column. The interactions are categorized into three exclusive types of epistasis: synergistic, , , and share the same sign (and are non-zero), antagonistic, and share the same sign, but has opposite sign, and sign epistasis, , and are of opposite sign and is non zero.