Contents

23 December 1994
Vol 266, Issue 5193

About The Cover

DNA repair enzymes have been selected for this year's Molecule of the Year. They form a molecular maintenance crew that works 24 hours a day to cut out and replace damaged pieces of the double helix. Their labors prevent an overaccumulation of mutations, preserving the information in the genetic code and preventing cancer. See Editorial on page 1925, Molecule of the Year on page 1926, and Perspectives beginning on page 1954. [Illustration: R. J. Kaufman, Brookline, MA]