The physicist who left venture capital to build the search engine for the immune system - one rare cell at a time.
A rooftop in Boston, a box of soil, and a row of vegetables that had no business surviving a New England winter. That was Li Sun's idea of a hobby while she finished a PhD in applied physics. She likes to make things grow where they probably shouldn't. Years later, in a lab beside UCSF Mission Bay, she is doing it again - except the thing growing is a company, and the soil is a microfluidic chip the size of a credit card.
Sun is the founder and CEO of Shennon Biotechnologies. The pitch is deceptively plain. Inside every cancer patient there are immune cells that already know how to fight the tumor. The trouble is finding them. They are rare, they are quiet, and the standard hunt takes weeks or months of painstaking lab work. Shennon's platform reads millions of immune cells, one at a time, by measuring what each one actually secretes - and it does the whole sweep in a few hours.
"While current approaches take weeks to isolate a T cell target, our technology platform can do this in a matter of hours, with more precision," she has said. That is the entire bet, compressed into a sentence. Speed plus selectivity. The needle, and a machine that makes the needle shout.
Most biotech founders come up through the lab. Sun took the scenic route. She spent five years as a deep-tech venture investor - first at Bessemer Venture Partners, then as a partner at Foundation Capital - evaluating the kind of technology-driven startups that promise to solve global-scale problems. She saw a lot of decks. She learned what a hard problem looks like before anyone has solved it.
Then she did the unusual thing. She stopped funding the technology and went to invent it herself. In January 2021 she founded Shennon. By March 2023 the company stepped out of stealth with a $13 million seed round led by DCVC, with Foundation Capital, AV8 and a roster of angels along for the ride.
Founder & CEO, Shennon Biotechnologies. Single-cell immunotherapy, built in San Francisco.
ROLE — Founder / CEO
FOUNDED — Jan 2021
SEED — $13M (DCVC, 2023)
HQ — San Francisco, CA
FIELD — Immuno-oncology
“Passionate about inventing technologies that transform human life - and turning those technologies into products that have a lasting positive impact on the world.”
Millions of immune cells get sorted to the single-cell level on a microfluidic biochip. No averaging, no crowd noise - each cell gets its own moment.
Instead of guessing from surface markers, the platform measures what each cell actually secretes - the functional proof that it is fighting the right enemy.
Out of the millions, the rare effector T cells are pulled out and their TCR or antibody targets identified - target discovery in about a day.
Shennon starts with solid tumors - the hardest room in oncology. Solid tumors hide, they shape-shift, they wear the body's own disguises. Finding the immune cells that can crack them is exactly the rare-cell problem Sun spent a decade learning to solve in physics. But the roadmap doesn't stop at cancer.
The plan is to push the platform into autoimmune disease next, and eventually into the full sweep of immune-system conditions. The logic is the same every time: if you can read what each immune cell is doing, faster and at scale, you can find the right target before the disease has time to win.
"Our technology platform can increase the overall probability of generating a curative treatment in a shorter period of time for cancer patients," Sun has said. Note the word - curative. Not managed. Not slowed. She is aiming at the cure, and she wants to get there faster.
Her investors noticed the same thing. "Li is leading a company with a bold vision to revolutionize the field of immunotherapy," said DCVC partner James Hardiman. AV8's Ruchita Sinha put it more personally: "From the first time we met Li, we have been very impressed with her passion and vision for building a company that addresses existing bottlenecks."
“Li is leading a company with a bold vision to revolutionize the field of immunotherapy.”
JAMES HARDIMAN, DCVC
“Impressed with her passion and vision for building a company that addresses existing bottlenecks.”
RUCHITA SINHA, AV8
She built a rooftop vegetable garden in Boston. The woman who hunts rare cells also coaxes tomatoes out of city air.
Hiking, painting, gardening. The hobbies of someone who likes patience and pattern - which is most of biology, too.
The company name nods to Shennong, the legendary figure of Chinese medicine who reputedly tasted hundreds of herbs to learn their effects.
She is "trained to always apply first principles to find the simplest, most direct" path - a physicist's reflex pointed at biology.