Christopher Lyles, the 1st U.S. patient and the 2nd worldwide to receive a stem cell trachea transplant, died this month of unknown causes.

Lyles received an experimental trachea grown from his own stem cells and cultivated in a bioreactor made by Harvard Bioscience (NSDQ:HBIO) in November 2011.

"Christopher was a recipient and strong advocate of stem cell therapy," Lyles’ family said in a prepared statement. "We do not want his journey to be in vain. We hope his bravery will pave the way for further research and development and acceptance of stem cell based therapies in the U.S."

Doctors created a trachea biologically identical to Lyles’ original organ by regenerating stem cells taken from his bone marrow, according to ABC News.

Lyles had undergone 7 rounds of chemotherapy and 33 rounds of radiation treatment for a rare form of trachea cancer prior to seeking out a transplant, a move that took him to Sweden for a 12-hour surgery at the Karolinska Institute’s Advanced Center for Translational Regenerative Medicine in Stockholm.

By January, Lyles was able to eat and speak on his own, the network reported.

"I think this is a viable solution to this type of cancer," Lyles had said. "I’m happy to have been a part of it."

Harvard Biosciences president David Green was not immediately available for comment.