Figure 1.

Using the appropriate null model. (A) Network of protein interactions in yeast. (B) Randomization of the network of protein interactions in yeast. The randomization provides the appropriate null model to study the relationship between form and function in the real network. In the null model, hub proteins are more connected to each other than in the real network. Additionally, the randomization lacks the modular structure of the real network (represented by different colours in panel A).