HSPD1 and anthrax infection: B. anthracis GroEL is highly immunogenic and generates stronger immune response.47 Mice pre-injected with GroEL are protected against anthrax infection, indicating that GroEL might be important for pathogenesis.48 GroEL is co-transcribed with the co-chaperone GroES and the GroEL–GroES complex mediates appropriate protein folding.