Dr. Nicole Urban of the Fred Hutchinson Cancer Research Center talks about the "holy grail" of biomarker research and explains the clues to cancer that doctors seek in patients.

Biomarkers, changes in a protein that indicate the progression of a disease, hold promise for different fields of medicine. NewsHour health correspondent Susan Dentzer reports on the use of biomarkers in the early detection of cancer.

The Nobel Prize in chemistry was awarded Wednesday to Roger Kornberg of Stanford University for his work on how cells use information in genes to produce proteins. He and his father Arthur Kornberg, also a Nobel laureate, discuss their achievements.