infection and disease are extremely stressful on the cell. when a cell is under stress, it naturally increases the production of stress proteins, including heat shock proteins such as hsp60. in order for hsp60 to act as a signal it must be present in the extracellular environment. in recent research “it has emerged that…chaperonin 60 can be found on the surface of various prokaryotic and eukaryotic cells, and can even be released from cells”. according to recent research, many different types of heat shock proteins are used in immune response signaling, but it appears that different proteins act and respond differently to other signaling molecules. hsp60 has been shown to be released from specific cells like peripheral blood mononuclear cells (pbmcs) when there are lipopolysaccharides (lps) or groel present. this suggests that the cell has different receptors and responses to human and bacterial hsp60. in addition, it has been shown that hsp60 has the capability “of activating monocytes, macrophages and dendritic cells…and also of inducing secretion of a wide range of cytokines.” the fact that hsp60 responds to other signal molecules like lps or groel and has the ability to activate certain types of cells supports the idea that hsp60 is part of a danger signal cascade which is involved in activating an immune response.