ERC and coevolution of expression are not coincidental. Pairwise correlation matrices show values of ERC (above diagonal) and coevolution of expression level (below diagonal) between glycolysis (A) and CCR4-NOT complex (B) proteins. Both ERC and expression coevolution are significantly elevated for both sets of proteins (P < 0.01). However, ERC is much stronger than expression coevolution in the CCR4-NOT complex, while it is the opposite case between glycolysis proteins. (Red) Values greater than 0.75; (orange) values between 0.5 and 0.75; (beige) values between 0.3 and 0.5.