It doesn't happen very often that two Nobel laureates who research the inner workings of cells speak back-to-back about their work within a few miles of each other.

Andrew Fire, a professor at Stanford University and a 2006 Nobel laureate, and Oliver Smithies, a professor at the University of North Carolina and a 2007 Nobel laureate, did Tuesday in the Triangle. Their talks spanned more than 60 years of molecular biology - tracing the understanding of what causes disease from two known proteins in the blood to thousands of known blood proteins.

At the National Institute of Environmental Health Sciences, Fire talked about research that is under way in his lab to better understand the inner workings of the immune system. Specifically, his team is looking at changes in immune cells' genetic code that indicate relationships between antibodies, immune system soldiers that attack bacterias and viruses, and antigens, the substances that trigger immune responses.

Fire and his team are trying to determine whether there are patterns in the relationships that would better explain the causes of allergies, autoimmune diseases such as rheumatoid arthritis, diabetes and muscular sclerosis and immune cell tumors like lymphoma. The research could also shed light on why some long-term HIV/AIDS survivors don't get sick and what causes donated bone marrow to attack the body of the patient who received the transplant, also known as graft-versus-host disease. Down the road it could help with diagnosis and treatment.

At the Research Triangle Park office, Smithies turned pages in his hand-written lab notebooks to illustrate stops along the intellectual road he traveled from 1948 to 1985, when he showed that DNA sequences can be inserted in living cells. Now he's working with nanoparticles.

During his about 60 years as a researcher, Smithies said some of his discoveries were accidental. Some he made after getting ideas from reading scientific papers. And some are the results of not giving up.

"Look for something a long way away," he said. "Try to get there." It doesn't matter if it doesn't work out, he added. The main thing is to have fun along the way.