TABLE 1.

Classification and characteristics of HSPs.

Classification	Subclassification and characteristics
HSP90	HSP90α is primarily found in the cytoplasm
	HSP90β is found in the mitochondria
HSP70	Constitutive HSP70 (HSC70) is found in the cytoplasm
	Inducible HSP70 (HSP72) is produced in response to cellular stress
HSP60	HSP60 (cytosolic)
	HSP60 (mitochondrial)
HSP40	Constitutive HSP40 is found in the cytoplasm
	Inducible HSP40 is produced in response to cellular stress
Small HSPs	HSP27 is involved in the regulation of the actin cytoskeleton
	HSP20 is involved in protection against cellular damage