Heat shock proteins are present in cells under normal conditions, but are expressed at high levels when exposed to a sudden temperature jump or other stress. Heat shock proteins stabilize proteins and are involved in the folding of denatured proteins. High temperatures and other stresses, such as altered pH and oxygen deprivation, make it more difficult for proteins to form their proper structures and cause some already structured proteins to unfold. Left uncorrected, mis-folded proteins form aggregates that may eventually kill the cell. Heat Shock Proteins are induced rapidly at high levels to deal with this problem. Increased expression of HSps is mediated at multiple levels: mRNA synthesis, mRNA stability, and translation efficiency