By Mike Fantini, as told to Sarah Kim

Patients with blood cancers like leukemia, lymphoma, and sickle cell often rely on a bone marrow transplant to save their life. About 70% of these patients need complete stranger for a donation, and are most likely to receive a successful transplant from someone between 18 and 44 years old.

Through the Give A Spit About Cancer campaign, DoSomething.org is activating young people to swab their cheeks and join the Be The Match registry, which finds donor matches for patients in need.

DoSomething's Chief Product Officer, Mike Fantini, was one of the thousands of people who swapped his cheek through Give a Spit About cancer. Below, the 29-year-old tells the incredible story of donating bone marrow, saving a young boy's life and later, meeting the boy and his family.

----------

In 2011, DoSomething.org had an in-office cheek-swabbing event to celebrate our first year running Give a Spit, and that was when I signed up for the national bone marrow registry through Be The Match. Two years later I got a call and was told that I might be a match for a ten year old with leukemia -- I still have the voicemail saved to this day. Shortly after receiving the call, I filled out a health history questionnaire and had blood work done, and it all confirmed that I was a match for this little boy.

A few weeks after that, I went in for the procedure, and honestly it was so much easier than I ever realized. The doctors gave me some anesthesia, wheeled me in, and before I knew it I was awake again, and the procedure was over. As soon as I woke up, the nurse asked if I was in any pain, I said a little, they gave me some more pain medications, and after that I felt as good as new. I was seriously shocked at how good I felt. The doctors gave me some pain medication for the next few days, but I only ended up taking them right before bed the first two nights to ensure I slept through the night. Beyond that I took Advil a few times and that's it! I was back at work 48 hours after my surgery.

A few weeks later, I found out that the procedure had gone well for my match also. There is a rule that recipients and donors can't learn each other's identities until a year after the surgery, but we were able to send anonymous letters back and forth through Be The Match. In late 2014 I was finally able to learn more about my match. He lives in Tennessee, his name is Hunter, but everyone calls him Bug. Bug loves playing baseball, fishing, and watching the Tennessee Volunteer football team. It was incredible to learn more about one another, and we were both so excited for the potential to finally be able to meet in the future.

Finally, this past fall, Bug and his family came up to NYC for a visit. Our families got together for dinner and had a great time catching up and getting to know one another better. It was a wonderful night. And became a very eye-opening experience for me.

Conceptually I knew that I had done a good thing by making this life saving donation. But it's really impossible to actually wrap your head around what it really means, especially because it was such a relatively simple process and experience for me. And even in that moment at dinner finally getting to meet Bug and his family, I had difficulty fully grasping everything.

That was until the end of the night as we were all saying our goodbyes. Bug's dad shakes my hand and looks me right in the eye and says, "Thank you saving my boy's life and keeping our family together."

And something about hearing it in person, looking directly into each other's eyes, both of us getting a bit swept up with emotion, being surrounded by his wonderful family put everything into a whole new perspective for me. And I just felt so fortunate to be able to help a family in need.

It's without a doubt the most incredible experience of my life and I definitely would encourage everyone to sign up who can.

Want to Give A Spit About Cancer? Learn more how you can swab your cheek to get started.