Biochemistry. A heat shock protein with the molecular mass of 70 kDa found in all organisms. It takes part in protein folding and helps the cell to survive stress.
Notation according to Cold Spring Harbor Meeting in 1996: Hsp (first letter capitalized) refers to the protein, hsp (lower case letters) to the gene. HSP (capitals) denotes the family in a certain range of molecular weight, HSP70 between 70 and 78 kDa.