HUB VULNERABILITY. “This makes them robust to random node failure relative to a network whose degree distribution is random, but it also creates a vulnerability to the loss of only a few hubs. Importantly, PPI networks are highly dynamic, as their constituents are often short-lived and can be modified (e.g. phosphorylation) to shift interaction preferences.” (PPI = protein-protein interactions).
http://www.biochemj.org/content/454/3/361?sa=X&ved=0CDkQ9QEwEWoVChMIzdjAo5n2xgIVovRyCh0HSAum