When you hear the name Riley Ennis, you might think of a top scientist or a Silicon Valley founder with years of experience. But what makes his story special is that his journey began much earlier—back when most teenagers were still trying to figure out what they wanted to study. Today, Riley Ennis is known as a biotech entrepreneur, a Thiel Fellow, the Co-Founder and Chief Product Officer of Freenome, and the mind behind early cancer vaccine research that amazed scientists and investors around the world. His work brings together simple ideas, smart technology, and a deep desire to help people live longer, healthier lives.
A Curious Mind with a Big Goal
Riley Ennis grew up in Northern Virginia, where family trips to the beach sparked his early love for marine biology. He was fascinated by horseshoe crabs after watching a PBS Nova program. Something about their immune system caught his attention. There was a special protein that acted like a “tag,” telling the crab’s body which cells to destroy. Riley began thinking: What if the human immune system could do something similar? Could this help treat cancer in a better way?
This simple question slowly grew into a real scientific idea. Riley wanted to help the immune system recognize tumor cells so the body could destroy them on its own. It was the start of a powerful vision. Looking back now, it’s clear this early spark shaped everything he would do next.
Turning an Idea Into a Real Cancer Vaccine
By the time Riley Ennis was in high school, he had already done something most people never dream of—he created the early version of a cancer vaccine. He worked in research programs at the University of Pennsylvania, Georgetown University, and the Sheikh Zayed Institute at Children’s National Medical Center. He learned molecular biology techniques, secured lab space, raised money, and even filed patents.
His idea was simple but bold. A human protein could act like that immune “tag,” marking cancer cells so the body could recognize and destroy them. Riley tested this model in mice and human cells, and the results were promising. This work became the foundation of his first biotech company, Immudicon, which he started as a high school senior.
Immudicon’s vaccine platform caught major attention. It formed partnerships with more than 14 pharmaceutical companies and was noticed by media giants like CNN, Forbes, Bloomberg, TEDx, Milken, and Johnson & Johnson. Riley proved that age does not limit innovation. What matters is vision, passion, and the willingness to keep learning.
Growing as a Scientist and Entrepreneur
After high school, Riley Ennis went to Dartmouth College, majoring in molecular biology. While studying, he continued working on cancer immunology, co-authored scientific publications, and became a Visiting Scientist at Novartis, where he explored immune-based therapies and protein technologies. He also built new skills by working at Foundation Medicine, Syros Pharmaceuticals, Adimab, and Emergent BioSolutions.
But Riley’s interests reached beyond the lab. He wanted to understand how companies grow, how teams work, and how strong culture shapes success. This led him to roles at Morgan Stanley as an analyst and Bridgewater Associates as an associate. At Bridgewater, he saw firsthand how good leadership and a healthy work environment can transform an entire organization.
During his time at Dartmouth, Riley also co-founded Mitosis, an accelerator program that helped student groups build startups by pairing them with faculty mentors. Everything he did—science, business, leadership, research—was preparing him for something bigger.
A Life-Changing Opportunity: The Thiel Fellowship
In 2013, Riley Ennis received the Thiel Fellowship, a prestigious award created by Peter Thiel, the PayPal co-founder. This fellowship gave Riley $100,000 and, more importantly, access to a powerful network of founders, scientists, and investors. Selected from more than 500 applicants, Riley joined the “20 Under 20” group of young innovators changing the world.
The fellowship encouraged him to leave Dartmouth temporarily and move to San Francisco, where he could turn his ideas into real companies. This step would soon lead him to co-create his most impactful work yet.
The Birth of Freenome and a New Vision for Cancer Care
After gaining experience in both science and business, Riley Ennis was ready for the next step in his journey. In early 2014, he helped co-found Freenome, a health technology company with one powerful mission: to detect cancer early using a simple blood test. The idea was bold but easy to understand. If doctors could find cancer early, when it is still small and easier to treat, more people could survive. Riley wanted to build tools that would make this possible for everyone.
At Freenome, Riley Ennis became the Chief Product Officer and later helped lead the company as Chief Operating Officer. His job was to guide the clinical and commercial development of Freenome’s tests. These tests are special because they use multiomics, machine learning, and the study of DNA fragments in the blood to find early signs of cancer. Instead of waiting for symptoms, Freenome looks for tiny changes in the body long before a tumor appears.
Riley often explains this in simple terms. Imagine your body telling a story through tiny pieces of DNA. Some pieces show normal health, while others show early trouble. Freenome’s tools read this story. They help doctors see early warning signs so they can act fast. It is a calm, gentle, and noninvasive way to look for cancer.
Why Freenome Stands Out
Freenome grew quickly because the idea made sense to scientists, doctors, and investors. The company raised a large $65 million Series A from well-known groups like Andreessen Horowitz, Google Ventures, Polaris, Founders Fund, and Innovation Endeavors. These investors believed in the future of early cancer detection and trusted Riley’s leadership and vision.
People often ask why Freenome became so successful. The answer is simple: the company brings together the best parts of biology, computer science, and medicine. Riley Ennis helped build a team where researchers, engineers, and doctors work side by side. He also brought the lessons he learned at Bridgewater Associates about strong culture and clear communication. These ideas helped shape Freenome into a place where big discoveries happen.
Under Riley’s guidance, Freenome created tests designed to help doctors not only detect cancer early but also choose the right treatment. This approach makes care more personal and more accurate. Riley calls it “early detection and early action.”
A Leader Who Blends Science and Heart
What makes Riley Ennis inspiring is not just his talent, but also the heart behind his work. His early interest in marine biology, his sister’s medical challenges, and his dream of helping the immune system fight cancer all shaped him from a young age. He carried these feelings into every lab, every meeting, and every company he helped build.
Riley’s work at Immudicon, Oncolinx, Foundation Medicine, Syros Pharmaceuticals, Adimab, and Emergent BioSolutions gave him a deep understanding of cancer biology and drug development. His time at Novartis taught him the importance of translational research—turning ideas into real treatments for real patients. His roles at Morgan Stanley and Bridgewater helped him understand markets, finance, and leadership.
He brought all these experiences into Freenome. This blend of science, business, and compassion is what makes Riley stand out. He is someone who listens, learns, and leads with purpose.
The Impact of Early Work and Recognition
Riley’s achievements have been recognized worldwide. He became a Thiel Fellow, joining the “20 Under 20” group of young innovators. He earned a spot in the National Gallery for America’s Young Inventors. His early vaccine research drew attention from CNN, Bloomberg, Forbes, TEDx, Milken, and Johnson & Johnson. His company Immudicon formed partnerships with over 14 pharma companies, showing how powerful his ideas were even at a young age.
These honors are exciting, but for Riley, the real reward is helping others. He often says that his goal is not just to build companies, but to build solutions. He wants to create tools that make the world healthier and safer.
Moving the Future of Cancer Detection Forward
Today, Freenome continues to grow, and Riley Ennis remains a key part of this progress. The company’s work is shaping the future of precision diagnostics, multiomic biomarker discovery, and noninvasive cancer screening. Riley’s vision of using simple blood tests to read the body’s signals is becoming a reality. These tests offer hope, comfort, and early answers to people who need them.
Riley believes the future of cancer care lies in early detection and smart technology. He sees a world where a quick blood draw can reveal important information long before a disease becomes dangerous. This dream keeps him moving, learning, and creating.
A Legacy of Innovation and Purpose
The story of Riley Ennis is a reminder that big ideas can come from anyone, even from a curious teenager watching a science show. His journey from studying horseshoe crabs to leading one of the most advanced cancer detection companies in the world shows the power of imagination, science, and heart.
Riley’s work helps us see what is possible when passion meets purpose. With every new test, discovery, and partnership, he moves us closer to a future where cancer can be found early, treated early, and—one day—no longer feared.
