ABOARD THE PAPAL PLANE – Even in the midst of a jam packed three-nation tour, Pope Francis took time to act as a pastor Monday morning, recording a video message for Lisandro Zeno, 25, a fellow Argentinean who was diagnosed last year with leukemia.

“Lichu, I was told about your illness, I pray for Jesus to give you strength and that he returns your health to you. Allow yourself to be led by God’s hand, and I ask you to pray for me. I bless you with all my heart, in the name of the Father, the Son and the Holy Spirit,” Francis said.

The 30-second blessing was recorded exclusively by Crux during the flight from Quito to Guayaquil, where the pope will celebrate a Mass for more than one million people.

Zeno, known as Lichu in his hometown city of Rosario, is a medical student and was a rugby player until his diagnosis last year. After several rounds of chemotherapy, it seemed he was in remission.

But last month, doctors told him he’d had a setback.

Now, he’s hospitalized and waiting for a bone marrow transplant after finding a compatible donor in Brazil. The procedure is set to happen in five weeks.

Zeno’s story became public when, motivated by his disease, he launched a campaign to generate consciousness of the importance of donating blood and bone marrow.

Then, when friends organized an online campaign to lift his spirits, his story went viral in Argentina: news anchors, rugby players, and soccer stars all filmed short messages for him.

As a result of the treatment, Zeno lost his hair. In response, his friends launched a social media “dare” with the hashtag #NoPasaNadaMaestro (“Don’t worry about it, boss”), shaving their heads and, more importantly to Zeno, registering and marrow and blood donors in hospitals and clinics.

Because of the specificity of the tissues needed to generate a match, international swaps like Zeno’s aren’t uncommon. The odds of ever actually being called on to donate are very low: According to the US-based “Be The Match Registry,” just one in 540 adults registered in the United States will ever need to donate bone marrow.

Bone marrow donation is a surgical procedure that takes place in a hospital operating room, with either local or full anesthesia. Most donors are able to return to work, school, and resume other activities within a week, sometimes as quickly as a single day.

Though Francis made no reference to marrow donation, he was told in writing that the video had two purposes: To lift Zeno’s spirits — who after his second hospitalization said, “the only message I have left is one from Francis” — and to help bring awareness to Zeno’s campaign.

With few caveats, the Catholic Church endorses organ and blood donation, in word and deed. Last year, the mayor of Rome told journalists that Pope Francis had asked him during a meeting to report the pontiff’s call for more widespread use of organ donation, and Francis’ predecessor, Pope Benedict XVI, was known to carry an organ donor card.