Kono Christo does not leave things to chance. He tracks his sleep with a Whoop band, cross-references it with an Oura ring, and gets tested for nearly 100 biomarkers each year. He followed the protocols of longevity researchers such as Peter Attia and Rhonda Patrick and had his blood tested every year for four consecutive years. He was optimizing his supplements, circadian rhythm, and protein intake.
Founding his second company at age 35, he was as passionate about the latest health research as anyone. His last medical checkup in 2025 was all green. “It was the best I’ve done in years,” he says.
And after training, his arm was swollen.
He didn’t think much of it at first. A week passed before he saw a doctor, who discovered two blood clots in his veins and scheduled surgery. But pre-operative testing changed everything. The doctor returned to the room and announced that no surgery was being performed.
“I see a lump 11 x 11 x 8 cm behind the sternum,” the doctor said.
The biopsy results confirmed something Cristo had never thought before. He had aggressive, rapidly progressing non-Hodgkin’s lymphoma. It is a rare diagnosis that affects approximately 1 in 420,000 people and is caused by a random genetic mutation unrelated to lifestyle, diet, or stress.
The tumor had only been present for about three months. It was supposed to reach stage 4 in about three weeks.
“It was a blessing in disguise,” Crist told this editor this week from his part-time home in Athens. “I found that because I was aiming for something completely different.”
What followed was an education about the limitations of the health care system and what determined patients can do about it using the tools currently available.
His first oncologist, a well-known expert, recommended the lighter of the two available chemotherapy regimens. Christo scheduled her first infusion for three days later. Then I asked for a second opinion the night before.
The second doctor did not hesitate. Because of Christo’s unique medical condition, he recommended a more severe treatment: continuous in-hospital IV therapy in cycles every three weeks for six months. With lighter treatments, his presentation success rate was about 60%. For the aggressive ones, that number was about 85%. Two world-class doctors. Directly opposite recommendations.
“As founders, we’re behind the wheel,” Crist says about the tendency of many people to accept what they’re told, and why more people shouldn’t. “You hear a lot of things, but you don’t have to follow the first piece of advice.”
He did not choose to just follow the second doctor’s advice. Over the next two days, he collected a total of 12 opinions. We tapped into our professional networks and reached out to hematologists and oncologists in the United States and abroad to seek as much buy-in as possible. The vote was 11-1 in favor of a more difficult path. he accepted it. He says the decision felt less courageous than logical. He was already a data-driven person, but now the stake felt existential to him.
Over six months of treatment, Crist approached chemotherapy the same way he approached building a company: a marathon sprint. Each sprint was a finite cycle, filled with data points every week. At the age of 18, he was required to serve in the military for 25 months in Cyprus, and he also put that experience to good use. He would make a good soldier, he told himself. Trust the process. 6 cycles. Get over it.
He wore the hoop all the time, and it was surprisingly accurate at predicting the day his immune system would hit rock bottom, sometimes warning him before symptoms appeared. He kept a diary of his symptoms using audio transcription, recording every shift, every side effect, every medication and counter-medication. He zeroed in on three variables: sleep, nutrition, and first and foremost, psychology. (“It moves the needle more than anything,” Crist said. “I’ve never asked, ‘Why me?’ There’s no useful answer to that question.”)
He entered everything into Claude: blood results, scan data, wearable output, diary entries. He’s not the only one using chatbots for medical guidance. A poll released in March found that one-third of American adults now use them for health information and advice. Stories accumulating online suggest that for some patients, AI is achieving what systems could not.
Experts are urging caution. Daniel Bitterman, clinical director of data science and AI at Mass General Brigham, told The New York Times in recent months that generic chatbots are often wrong and have “not been thoroughly evaluated” for personalized diagnosis.
Mr. Crist has no objection to that opinion. “It didn’t replace a doctor, but it helped me ask the right questions,” he says.
For a condition as rare as his (one that oncologists see once a year), he says, accessing a model that absorbed all of the medical literature wasn’t quite the same as a Google search.
This model was found to be significant at the end of treatment. His last PET scan, an imaging procedure used to detect active disease, had equivocal results. His oncologist started talking about a second treatment near his heart and lungs, possibly radiation therapy. It was a worrying development.
Christ did his homework again. He read that for this particular lymphoma, the false-positive rate on PET scans after treatment is about 60%. This statistic still amazes me. “It’s 2026,” he says. “Sixty percent.”
He fed Claude all three PET scans and an MRI, alerting him to a known but often overlooked phenomenon. In patients younger than 40 who are recovering from this type of lymphoma, the thymus gland may reactivate after chemotherapy, causing what appears to be active disease to appear on images. Considering his age and his unique scanning characteristics, the model estimated the probability of that explanation to be approximately 90%.
He asked for three further opinions. A fourth doctor confirmed it: thymic rebound. There was no active disease. No radiation therapy was required. He was clear.
Crist is still figuring out what the last year has meant to him, including his health, the way he works, and the way he thinks about his time. He founded his current company, Keragon, before any of this happened. This is an AI-powered platform that helps automate administrative tasks in medical settings.
But experiencing the system as a patient gave him a new perspective. He saw nurses and doctors buried in duties that had nothing to do with care. He underwent the same chemotherapy protocol as the 80-year-old woman, and side effects were managed with a chain of additional drugs, each posing its own problems. He says there’s no doubt we’ll look back on this era of treatment and cringe.
He now has most Sundays off. At lunches with friends, at home with his dog, he tries to engage in conversations that once might have felt like a distraction from work. A friend of VC’s told him years ago something he kept replaying over and over during treatment: “Be happy now.” He says it was one of the most difficult things to do, but he finally realized its importance.
He said he would be happy to talk to anyone going through something similar, share notes and compare experiences. He seems to mean it.
“That won’t happen in 10 years,” he says of what AI can already do for patients who want to use it. “It’s happening today.”
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