Abstract
Biological approaches to cancer therapy have gone through phases of early excitement and subsequent neglect and ridicule, and have now entered an era of renewed interest. Unlike Coley and his contemporaries a century ago we are using highly purified agents of impressive potency and specificity of action in our current studies. We have come a long way in dissecting their interactions in inflammation, immunity and hematopoiesis, but we have a long way to go in defining optimal conditions for their use in therapy. However one judges the promise biological agents hold for cancer therapy, it seems certain that they will be prominent subjects of future research.