"I am personally very saddened by the loss of Senator Kennedy. In my view, he was a true American hero who fought fiercely for the rights of all Americans to have decent and good quality health care. As a physician, this is what I admired about him the most. Yet, as a physician who consulted on his case, to help advise him and his family how to battle this disease, I admired him for his tenacity in dealing with the situation and wanting to do everything possible to defeat the tumor that eventually took his life."
Dr. Sam Gandy, professor of Alzheimer's disease research at Mount Sinai School of Medicine in New York City, said that Kennedy's legacy in supporting medical research will echo long after his death.
"On DNA research, in vitro fertilization, fetal tissue research, and most recently, stem cell research, 'Teddy' was always there," he said. "In each of these debates, Senator Kennedy held steadfast to principles and goals famously set out by his brother, the late President Jack Kennedy.
"In the same way that Jack Kennedy took us to the moon and beyond, Teddy led us inward, to the cells, genes, and DNA that hold the keys to ourselves and our maladies. We in science and research -- especially in these very lean years for the NIH -- already miss his ability to engage legislators and laypeople and move these debates forward."
Those in the medical field whose lives he touched will remember him as well.
"He was always helpful. He always made things happen," Cohen said. "Sometimes, I wear a Kennedy campaign hat around town. I do so proudly and always will."
Dr. Atif Haque contributed to this report.