Graph of protein-protein interaction. (A) The network of the 1548 proteins of the yeast proteome and their interactions.¹⁵  Proteins with different functions are represented by different colors and include lipid metabolism (yellow), cell structure (green), membrane fusion(blue), chromatin structure(gray), and cytokinesis (red). (B) Because of node and edge density, a subset of the network is magnified to reveal the complexity of components and interactions. (Figure from Uetz et al¹⁵  reprinted with permission from Nature.)