As previously mentioned, hydrophobic forces play an important role in the overall structure of proteins. These hydrophobic forces may also cause proteins to aggregate. If a protein molecule is placed under strain, it may deform slightly. This protein deformation is called denaturation. If a protein is irreversibly denatured, it can longer function as it is supposed to, and the protein has no value as a product. Thus, there is a limit as to how much strain a protein molecule can uhdergo. A slightly denatured (reversibly denatured) protein may expose its hydrophobic regions, which are normally located in the center of the molecule and are normally shielded from the protein molecule's surroundings. If other protein molecules in the solution are also slightly denatured, the proteins' hydrophobic regions may interact with each other. In essence, one protein molecule's hydrophobic region may bond with another protein molecule's hydrophobic region. Each protein molecule may interact with several other protein molecules, causing the formation of a protein aggregate.