With a hug and a smile, President Barack Obama awarded Dr. Janet Rowley the Presidential Medal of Freedom.
After graduating medical school at the University of Chicago, Dr. Rowley didn't dive right into research.
"She got married and gave birth to two sons making medicine a hobby and her family a priority," said Pres. Obama during the ceremony.
Pursuing that hobby, in 1972, at her kitchen table, she discovered that specific types of cancer are caused by certain genetic mutations. That research changed the way scientists look at and treat cancer.
"All of us have been touched in some way by cancer, including my family. And so we can all be thankful that what began as a hobby became a life's work," said Obama.
Also honored on Wednesday was a who's who of the last hundred years. Among the 16 receiving the medal were Sandra Day O'Connor, Sydney Poitier, Desmond Tutu, Billie Jean King, and Steven Hawking.
Senator Ted Kennedy was also honored at the event but because of his ongoing battle with brain cancer his daughter accepted the medal on his behalf.
"These extraordinary men and women, agents of change ... forgotten corners of this world," said Obama.
At age 84, Dr. Rowley still rides her bike every work day between the lab and her Hyde Park home. She loves to show off her garden and says she had no idea the impact her discovery would have.
"As you're living this life, you don't think of yourself as a pioneer," said Dr. Rowley.