Back in 2016, just before his 21st birthday, Kristopher Boesen’s life changed forever when he lost control of his car and crashed into a tree and lamp post. He nearly died in the crash, and while he was able to survive, Kristopher was left paralyzed from the neck down because of it.

Doctors told Kristopher that he would likely never regain control of his body’s movements, but they also offered him the chance to participate in an experimental procedure involving stem cells. This procedure was designed to repair injured nerve tissue by replacing damaged cells, and though there was no guarantee it would work, Kristopher jumped at the chance to try it.

Charles Liu, MD, Ph.D., director of the USC Neurorestoration Center, led the surgical team behind the procedure, and he teamed up with Rancho Los Amigos National Rehabilitation Center and Keck Medicine of USC to make it happen. During the procedure, they injected an experimental dose of 10 million AST-OPC1 cells into Kristopher’s cervical spinal cord. They were able to get these cells through an in-vitro fertilization of donated eggs.

The weaning process afterwards typically takes three weeks, but Kristopher was able to do it in just three days with the support of the dedicated medical team.

Kristopher started seeing improvements after three weeks, and once eight weeks had gone by, his motor functions had drastically improved. By then, he could do things like operate his wheelchair himself, answer the phone, and even write his own name.

Three months after the procedure, Kristopher had recovered two spinal cord levels, meaning he could brush his teeth, work on a computer, and do pretty much everything using his arms and hands.

Doctors have been heartened by the success of the procedure on Kristopher, saying that it could be used to help countless people. One day, they hope to use the procedure to help patients diagnosed with diabetes, Parkinson’s disease and cancer.