So far, Alex's foundation has helped pay for nearly 300 cancer studies, some of them at the Children's Hospital of Philadelphia.
One of Alex's doctors, Yael Mosse, and her team studied a link between cancer and a hereditary gene mutation called anaplastic lymphoma kinase, or ALK. This mutated ALK gene seems to make certain types of cancer grow.
"We kind of had a hypothesis in the lab that if we could turn it off, it may turn off the growth of the cancer, if this cancer is, indeed, dependent on this gene, if it's really being fed by this gene," said Dr. Mosse. "It's like the fuel for the cancer.
And crizotinib -- a drug already used to successfully treat lung cancer in adults -- can sometimes turn OFF that mutated ALK gene.
Dr. Mosse says that drug therapies like crizotinib target very specific types of cancer, and can do a lot of good for small groups of patients.
"We have to be smarter than just giving drugs that kill rapidly-dividing cells," she said. "We have to give drugs that are turning off something that's driving the cancer."
So, using money from Alex's Lemonade Stand and other sources, doctors were able to fast-track a federally-funded crizotinib trial for nearly 80 children.
"Younger kids have tolerated it really beautifully," said Dr. Mosse, "with very few side effects."
And what happened? "We saw some pretty dramatic responses in children who have lymphoma that's driven by this gene, ALK," Dr. Mosse said.
"When you say 'dramatic response,' what do you mean?" asked Smith.
"We saw the cancer go away within days and weeks. Go away completely."
It didn't help everyone, but one group with a very specific type of lymphoma, the difference was huge.
One of them was Zach Witt, of Berks County, Pa., who at age six was near death. But after only a few days on crizotinib, Zach got out of his hospital bed, to the amazement of his parents, Pam and John.
"We came home within a few days of that, and he got out of the car and got on his bike and started riding his bike," said Pam Witt. "And we just stood at the car and cried. Like, wow. Wow."
Now, two years later, Zach is still on the drug, and is as active as any other kid his age. "The bottom line is that Zach is a walking miracle," said Pam.
But "miracle" is an awfully big word.
Dr. Peter Adamson heads up the Children's Oncology Group at the Children's Hospital of Philadelphia Research Institute.
When asked if crizotinib is a cure, he told Smith, "Not yet. I think crizotinib, we hope, when added to other treatments, may become a cure. But right now, it is a promising treatment for a small number of children with certain cancers."
And that brings us back to Edie Gilger. After four major surgeries and 14 rounds of chemotherapy, the little girl's tumor was still growing, and her parents figured they had nothing to lose.
In her gut, said Emily Gilger, "I expected it not to work. The chemo didn't work. The surgeries didn't work. So, I was just sort of like, 'All right. Well, we'll try it. I'll give anything a shot for three months.' "
After four weeks on the crizotinib trial, they gave Edie a routine scan to see if her tumor responded, and got what might have been the shock of their lives.
"The radiologist called me before I even had a chance to walk over and look at the scan and said, 'Her surgery was a success and the tumor's all gone,'" said Dr. Mosse. "And I said to the radiologist, 'She didn't have surgery.'