Great to have my sisters here, sally-ann and dorothy. It's great to see you to celebrate. This is a celebration. It's wonderful to have all of you here. And wonderful to have all of you respond to... See More
Great to have my sisters here, sally-ann and dorothy. It's great to see you to celebrate. This is a celebration. It's wonderful to have all of you here. And wonderful to have all of you respond to robin's story, as we well. I think that was the goal. So many folks have told us their stories. And we want to share with you about spreading the word on how important it is to be the match that can save someone's life. Yes. Reporter: From the beginning. We've often said to our viewers, you are family. And we want you to hear things from us. Reporter: From that very first emotional announcement. All that prepared me for a bone marrow transplant. Reporter: Robin was clear on one thing. Using this personal setback to spread life-saving information to others. Bethematch.Org said they got a tremendous amount of response. Unbelievable. Wanting to be a donor. This really means a lot. Reporter: None of us could have guessed how quickly these seeds of knowledge would grow into life-saving action. Thas a cool opportunity to have. Reporter: Hundreds of miles away, tim gilligan logged on to his computer and saw this. Are you ready to meet this young man? I'm ro meet the man who saved my life. Reporter: Our segment on the meeting of a bone marrow donor and the woman he saved. I just want to say thank you. What an effect he had on someone else's life at such a young age. What an awesome thing to do. I went home that night and signed up the same night. I came home that night, i found something we're doing. He was really excited about it. He was, we're going to do this. Reporter: The gilligans had been looking for a way to teach their two, small boys the importance of helping others. This seemed like the perfect life lesson. I didn't know anything about the registry and how easy it was to sign up. Reporter: Some people who sign up to be a donor, could never be asked to donate. But fate had a different plan for tim. His phone rang two months later. I did it in late august. And I think it was october that I got the call that I was a match. Reporter: Somewhere in the world was a woman with leukemia. And tim was a perfect match. This is exactly why you sign up. It could be someone's mother, sister or aunt. She's someone to someone else, even though we don't know her. When you sign up or do anything in good in general, in some way, you're doing it to help someone else. But it's also sort of selfish reasons, as well, because it makes you feel good. Tim gilligan, I'm here for an apartment. Reporter: At the crack of dawn one cold, january morning, tim and kerra made their way to the dana farber institute in boston. You are a hero. And you know that. Reporter: And started the process of donating. An hour later, those first, precious stem cells start to flow. There's a lot of disconceptions about donated stem cells. It's an easy process. Some donors experience mild fatigue and mild joint pain. But that usually subsides within a couple of days of donation. Reporter: Eight hours after tim came into the hospital, mission accomplished. It was like sitting in a chair all day, watching movies. Reporter: A cooler with precious cargo races out the door, on the way to that leukemia patient. I want robin to know that she did have an impact. She did the show. She put it on the air. But it worked. Someone got matched. Now, tim is going in a few months later to potentially save this woman's life. Reporter: It's an ongoing chain of hope. From robin's journey. To tim's journey. To the new mission of those life-saving cells, giving someone a second chance. He understands, daddy's going to help a sick lady. I want them to know that he did everything he could to help someone he doesn't even know. That's what it's all about. What an example he is for his children. And that's why we do what we do. My sister, sally-ann, my sister, dorothy. And everyone knows sally-ann, you were my donor. That brings back some memories in watching. Oh, yes. And it also brings up, to me, the tremendous feeling of accomplishment to be able to know that there's something in your body that can help somebody else. In my case, my sister. And I just want to get the word out to as many people as possible. Please, join the registry. Please, join the be the match bone marrow registry because there's somebody out there that could use you. And sometimes the fear, what's going to happen? How do you feel? People have been asking me all along. I feel fine. It was the easiest thing in the world to be a donor. I'm amazed at your strength. You were the one who was strong. You were the one who had to endure so much in order to receive the transplant. You went through the chemo. And you stood the test. You stood the test. You passed the test. And you know that there are prayers that went -- my prayer partner, phyllis alexander, who is here today. Phyllis and I pray every, single day. I remember when you were praying when they were doing the swabbing. I thought dorothy, because we're closer in age, that dorothy was going to be the donor. People think, we all have siblings on this couch, and we feel that it will be automatic. And dorothy was not a match. And sally-ann was. What a blessing you were not because you were there to take care of momma. We all have a role to play in our family. I knew I wasn't going to be the match. I think it would have overwhelmed me. And it was a privilege and an honor to be there with mom and take care of her. And so many people, though, did so many things for you on the coast, with the swabbin' for robin, and the mississippi gulf coast, boys and girls club. You know, we just -- people just love you. And we are just so grateful t all of them for it. We are. We're following mom's legacy. And you all were there, everyone on this couch was there, when momma passed away. You came down to mississippi. George, you left the convention. The democratic convention. Boy, I saw -- how much the community loved you. And I saw some strong genes there. Morning television, as well, in new orleans. And your station has done a remarkable job. I can't say enough about wwl. And gives the call letters. As well as the entire metro area. New orleans metro area. They were out in drives. They answered the call, as well. And there's been so many prayers. And this family, I want to say, to abc, you truly have been the real deal. You've been there for robin through thick and thin. And we cannot thank you enough for all you have done for our sister, robin. I know going home, for your mother's home going, I was so struck by that community. It was an overwhelming feeling of welcome, of comfort, of support. And it all made perfect sense, all of a sudden, to see you all there, with the people from which you sprung. It was amazing. It was amazing. I do want to say something. We do have a brother. We have a brother. And we were recently all together down on the coast. And my brother is a schoolteacher in houston and a basketball coach. And he took time off to be with us, just a short time ago. So, he wasn't able to take time off again. But what a wonderful blessing it is to have family and extended family here. You are our family. It's we love having you here. If you need more, because there's a lot more of robin's journey, by the way. There's a special "20/20" that's happening this friday, at 10:00, 9:00 central. Guess whose face is going to be glued to that set? Mine. By the way, be the match. Let's make a difference for somebody out there. More coming up.
This transcript has been automatically generated and may not be 100% accurate.