Seeking nature secrets which could give people longer lives, four scientists worked directly with a key part, and no others. They were working with 941 main heart arteries which had been removed from as many bodies.
The first question to be answered was which arteries among the 941 were the most extensively "hardened," since "hardened arteries" are one of the chief reasons why people don't live longer than they do. To get that answer was largely a matter of sorting arteries.
But comparing the most hardened with the least hardened arteries gave no clues to why one set should be more "hardened" than the other set. This second question was the payoff one and the scientists, of course, would have liked for the arteries themselves to provide the answer.
