The extraction of RNA in molecular biology experiments is greatly complicated by the presence of ubiquitous and hardy that degrade RNA samples. Certain RNases can be extremely hardy and inactivating them is difficult compared to neutralizing. In addition to the cellular that are released there are several that are present in the environment. RNases have evolved to have many extracellular functions in various organisms. For example, a member of the superfamily, is secreted by human skin and serves as a potent antipathogen defence. For these secreted RNases, enzymatic activity may not even be necessary for the function. For example, immune RNases act by destabilizing the cell membranes of bacteria.