Proteases, also known as proteolytic enzymes, are enzymes that break down proteins in living organisms. Proteases play a critical role in various physiological and biochemical processes, including DNA replication, gene expression, wound healing, and immune function. They are also involved in digestion; for example, the human stomach contains proteases that help to break down amino acid chains found in proteins. Protease enzymes are used in many pharmaceutical and industrial applications, such as food processing, bioremediation, and pharmaceutical production. A variety of proteases can be found in nature as part of the bodies of living organisms and in a variety of environments from the soils to the oceans. Proteases can also be manufactured in a laboratory to be used for a specific purpose. In addition, research is underway to find new potential uses for proteases, such as in biocatalysis and the production of biopolymers materials.