At just 6 months old, Jack Marquis was suddenly given four weeks to live. After he was born with complex congenital heart defects, Jack's doctors in California had performed two open-heart surgeries that they thought would save Jack's life. But just when they thought he was out of the woods, Jack's condition suddenly began to deteriorate rapidly.

"On top of everything else, we learned he had a rare condition called pulmonary vein stenosis," says Jack's father, Andrew. Pulmonary vein stenosis causes narrowing of the veins that carry oxygen-rich blood from the lungs to the heart. The narrowing is a result of abnormal cell growth that builds up and seals off the veins.

While everyone else was telling Andrew and his wife, Amy, to cherish what little remaining time they and their two older boys had left with Jack, one cardiologist recalled that all the way across the country, a Boston Children's Hospital team was kicking off a brand-new clinical trial, using chemotherapy to combat pulmonary vein stenosis by blocking abnormal cell growth. Soon, Boston Children's was on the phone, arranging for a medical flight to transfer Jack to Boston.

"Do we fly back and forth to Boston, or do we move to Massachusetts?" Andrew says he and Amy asked each other. "All roads pointed to moving; we quit our jobs in California that same night and sold everything."

After arriving at Boston Children's, Jack began the trial treatment designed by cardiologist Dr. Kathy Jenkins and oncologist Dr. Mark Kieran, taking a leading-edge chemotherapy pill dissolved in apple juice each night. While pulmonary vein stenosis usually progresses very quickly, Jack immediately began to improve after starting treatment. After two rounds of therapy over the course of three years, Jack's condition stabilized.

Today, Jack is 4 years old and the only medication he needs to take is aspirin. He plays rambunctiously with his two older brothers and has lived to meet his 2-year-old brother and, in May 2017, his newborn baby sister.

"Before we left California, Jack was so sick that he was sleeping 23 hours a day. We worried about throwing chemotherapy into the mix," says Andrew. "But what drove us to make our decision to do the clinical trial in Boston was knowing that we didn't ever want to look back and wonder if there is something else we could have done to save Jack's life. Coming to Boston Children's turned out to be the best decision we ever made."