Delaney Van Riper was exhausted. It was the summer of 2017 and she’d spent the previous day touring UC Santa Cruz’s cliffside campus, getting her student paperwork in order, and meeting some of her 4,000 fellow incoming Slugs. Now, dressed head-to-toe in sweats, she was ready to nap in the backseat for the ride to her family’s home three hours away in Sacramento. But first, she had to stop at a glass and granite building in San Francisco’s Mission Bay, roll up her sleeve, and give some scientists she’d just met a few tubes of blood from the crook of her arm.

While Van Riper spent the next year navigating new roommates and freshman poetry classes, researchers at the Gladstone Institutes were busy reprogramming her blood cells into stem cells and then neurons, growing them in incubators by the million, and sending in Crispr systems to try to cut out a troublesome mutation lurking on the short arm of her longest chromosome.

LEARN MORE The WIRED Guide to Crispr

Van Riper, now 19 and a sophomore literature major, was born with a rare genetic disease called Charcot-Marie-Tooth, or CMT, which is slowly eroding her nerve cells’ ability to ping messages back and forth between her brain and her muscles. Doing things with her hands and feet, like walking and holding a pencil, has been growing progressively harder. But last year she became one of a handful of patients whose cells are undergoing experimental Crispr procedures at Gladstone that may one day be used to rid them of their genetically-determined disabilities.

In September, UC Berkeley biochemist and Crispr pioneer Jennifer Doudna announced she was opening up a lab across the Bay to establish the epicenter of a whole new field of medicine: genome surgery. As an ever-increasing crop of Crispr drug companies collect capital and race toward clinical trials, Doudna saw an opportunity for someone had to take an expanded, more inclusive view. She found a home for it at Gladstone, a nonprofit biomedical research center with hundreds of scientists and an affiliation with UC San Francisco and its clinical programs. What she envisions is the development of procedures closer to how surgeons slice out malignant tumor tissues with scalpels today. Except tomorrow’s genome surgeons will use Crispr’s molecular scissor function to remove or replace faulty genes—curing diseases at their genetic source code.

“We’re focused on what’s going to be best for patients in the long run, not simply what product can we quickly bring to market,” says Doudna. Though also the co-founder of a number of Crispr-based medical ventures, she worries that pressures for them to quickly turn a profit will leave behind many rare genetic diseases, each caused by a constellation of unique mutations that all require custom-built tools to fix them. And then there’s the question of the affordability of the treatments that do make it to market. Lowering the price tag for patients and making Crispr a sustainable technology is something more readily sorted out in a nonprofit setting, says Doudna. “We need to step back and figure out how to ensure in the future that this technology is not something only available to the 0.1 percent.”

Cost isn’t the only challenge. There’s also the problem of getting Crispr into the right cells, and into enough of those cells to make a difference. You can teach cells to build Crispr systems themselves, with instructions ferried in by innocuous viruses, but that approach makes it harder to control Crispr’s cutting action. You can coax Crispr into the cell directly by coating the protein complex itself in fat particles, but it’s not very efficient and it’s hard to direct. How will physicians deliver gene editors to tissues deep inside the human body, like the heart, or the brain?