AGES: 53, 33 and 46
OCCUPATION: Stem-cell researchers at Harvard
NUMBER OF TIME COVERS: 0
PREVIOUS APPEARANCES ON THE TIME 100: 0
PRO: Trio of researchers who announced that they would rely on nongovernmental funds to begin cloning human embryos and develop stem cells to be used for modeling various diseases.
CON: It's still controversial work, and any clinical application is at the very least a decade away.