Figure 2

'Fit' test of a candidate gene in a network gap. We use a self-consistent test in which a known gene E4 is removed from the network, leaving a gap in its place. We then: 1, put candidate genes in the gap one by one; 2, determine the function value for every candidate gene (Equations 1 to 3); and 3, rank all candidate genes based on their function values. In the figure we show an example when the correct gene E4 was ranked as number 6.