Robin Roberts has watched "Late Show With David Letterman" countless times before.
But the "Good Morning America" co-anchor had never appeared on the program. Not until Tuesday, when she visited "Late Show" to promote her new book, "Everybody's Got Something.""
She posted a photo while waiting backstage.
Roberts spoke with Letterman about the medical obstacles she has faced and overcome. Roberts, a breast cancer survivor, was later diagnosed with myelodysplastic syndrome, or MDS, a rare blood disorder.
She underwent a bone marrow transplant in 2012, receiving donor cells from her sister, Sally-Ann. Through it all, she has maintained a positive outlook, saying she wouldn’t change a thing.
"I can look at you right now and say I am healthier and happier than I've ever been," Roberts, 53, said. "That's all that matters."
Letterman remarked on the book's title, saying how appropriate it is. "Nobody gets a free ride," he said.
"You think you’re the only one," Roberts said of life's obstacles. "And my momma would say, 'Honey, everybody's got something.' Everybody's got something, not just a challenge, but something to give to help you get through that challenge."
After taping the appearance, Roberts had a parting message for Letterman: