This chapter on cell dynamics and the role of the actin cytoskeleton should be considered as a snapshot of a rapidly evolving field of research. In the last three years, PubMed lists 4,000 articles with the two key words actin and cytoskeleton. Indeed, many of the fascinating topics we work on today such as actin filament branching and severing, connection of the actin cytoskeleton to membrane-associated protein complexes, and the behavior of actin bundles commonly termed stress fibers receive negligible mention here. The field is very rich, and the inquiries are diverse. It is afruitful field of research with much fundamental biology and biophysics to be discovered.

Can we point to specific therapies that could be influenced by research in the areas described in this chapter? One possibility is understanding how the endothelium acts to realign and create small-vessel proliferation in cancerous tissue. Finding means to defeat the invagination of tumors would create the possibility of starving growing tumors and killing cancerous tissue selectively. The motility of the endothelium depends intimately on the organization and turnover of the actin cytoskeleton.

A second grand challenge to which this research points is understanding the mechanisms of atherosclerosis proliferation. A key step is the trans-endothelial migration of leukocytes and an inflammatory response cycle that leads to intimal smooth muscle cell proliferation. In order for the leukocytes to cross an intact layer of endothelial cells, the cells must first stick to the endothelium and then induce the underlying endothelial cells...