ABSTRACT
These are innumerable2. We have some idea of where bone cells come from and what they do (Chapter 2), but we have very little idea of how they ‘talk’ to each other. Legions of putative cellular messengers (cytokines) are described, but nearly all research is conducted in vitro on cells of dubious derivation and little applies in vivo to the human skeleton. Despite this-and since we must start somewhere-it remains important to unravel the nature of the linkage between the osteoblast and osteoclast, as these so-called ‘coupling factors’ are likely to be central to skeletal biology.
