DnaJB2 is a member of the DnaJ family. The DnaJ family is one of the largest of all the chaperone families which has evolved with diverse cellular localization and functions. DnaJB2 are important mediators of proteolysis which are involved in the regulation of protein degradation, exocytosis and endocytosis. The DnaJ proteins play a significant role in the HSP70 chaperone machine by interacting with HSP70 to stimulate ATP hydrolysis. DnaJB2 is expressed almost solely in the brain, with the highest levels in the frontal cortex and hippocampus.