Berridge, M.: "Cell Signaling: A Tale of Two Messengers," Nature, September 1993, pages 388–89. A discussion of second messengers and their functions in cell signaling.

Citi, S.: "The Molecular Organization of Tight Junctions," The Journal of Cell Biology, April 1993, pages 485–89. An in-depth, technical look at how tight junctions are organized in the cell.

Darnell, J., H. Lodish, and D. Baltimore: Molecular Cell Biology, ed. 2, Scientific American Books, New York, 1990. A good cell biology text, with particular strengths in cell-to-cell interactions.

Horwitz, A. F.: "Integrins and Health," Scientific American, May 1997, pages 68–75. A fascinating discussion of the role of adhesive cell surface molecules called integrins in a variety of cell functions.

Linder, M., and A. Gilman: "G Proteins," Scientific American, July 1992, pages 56–61. A good, basic discussion of what G proteins are and how they work. Gilman, the second author, won the 1994 Nobel Prize for this research.

Marx, J.: "Medicine: A Signal Award for Discovering G Proteins," in "Eight Get the Call to Stockholm," Science, October 1994, pages 368–69. An account of how Rodbell and Gilman received the 1994 Nobel Prize for Medicine or Physiology for their work on G proteins.

Putney, J.: "Excitement about Calcium Signaling in Inexcitable Cells," Science, October 1993, pages 676–78. A discussion about calcium in the body, its role as a second messenger, and signal transduction.