Fig. 1
From: Normalized L3-based link prediction in protein–protein interaction networks
Principles behind link prediction in PPI networks. (a) and (b) illustrate conditions that would lead CN and the L3 principle, respectively, to predict that an edge between the two non-adjacent nodes x and y is in fact missing. (c) A graphical representation of the occurrence of a physical PPI between protein x and protein y. (d) Using the abstraction in (c), if the PPIs are arranged as shown on the left, we can infer the existence of a PPI between protein y and protein x as shown on the right