{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"70 kDa heat shock proteins (HSP70) are found ubiquitously in virtually all living organisms, facilitating protein folding and protecting cells from heat stress and toxic chemicals. HSP70 proteins have 3 functional domains: N-terminal ATPase domain, substrate binding domain, and a C-terminal domain that serves as a “lid” for the substrate binding domain. HSP70 binds tightly to partially synthesized peptides and prevents them from aggregating and rendering nonfunctional. HSP70 also inhibits apoptosis by blocking the recruitment of procaspase-9 to the Apaf-1/dATP/cytochrome c apoptosome complex. Studies show a variety of tumor cells can express HSP70 with seemingly contradictory functions such as promotion or inhibition of apoptosis and lysosomal cell death and promotion or inhibition of tumorigenesis and angiogenesis."}]}]}