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Cohort 1

Reactorfield Cohort 1 companies, organizations, and scientific leaders
OrganizationRepresented byDescription
Alga BiosciencesDaria BalatskyAmy EisenbergMiranda GreenAlga Biosciences is turning enteric methane into calories for livestock. The YC-backed company has raised roughly $8M and was awarded a USDA Climate Smart Commodities grant. In controlled cattle trials, its Alga 1.0 formulation showed peer-reviewed methane-yield reductions of 39% and 63% at the studied inclusion rates.
EpistemeZachary MillerEpisteme is a new R&D institution, founded by Louis Andre and backed by Sam Altman and SoftBank's Masayoshi Son. It brings exceptional researchers, long-horizon funding, and operating infrastructure under one roof to pursue high-impact work across physics, biology, neuroscience, and engineering, modeled on Bell Labs and Xerox PARC. The team includes veterans of the Gates Foundation, DeepMind, and government ARPA agencies.
Foundation IndustriesJakob KnudsenFoundation Industries is modernizing the way frontier-hardware teams get parts made. The YC-backed manufacturer delivers rapid domestic CNC machining, including two-day turnaround, through a software-native workflow connecting CAD upload, specifications, quoting, payment, and production tracking. They will serve in the long term as the physical world API for the frontier.
Harvard UniversityKathy LiuKathy Liu is a Harvard PhD student and previous Fulbright Research Fellow designing smart materials for med tech, swarm robotics, tactile sensing, and bio-interfacing electronics.
Kopra BioAndrew BartynskiKopra Bio is a YC-backed oncology company developing viral immunotherapies that turn cancer cells into local factories for their own destruction. The UCSF spinout closed a $9.1M seed co-led by Boutique Venture Partners. Its first focus is glioblastoma, one of the most lethal and immunologically resistant cancers. In preclinical mouse models, Kopra pushed survival rates from 0% in controls to 90% in treated animals, with durable remissions and immunologic memory. Kopra is translating that viral-immunology foundation into a new approach to solid tumors.
Lume HealthJonathan MoustakisLume Health is building a continuous hormone-monitoring wearable: a wrist-worn, sweat-sensing platform built on a proprietary aptamer biosensor, starting with cortisol. The company was founded by Vicki Powell, a former Apple sensor engineer who holds three wearable sensor patents, and Jonathan Moustakis, MD, a nationally recognized physician-researcher. Lume has raised $2.5 million to date.
Marathon FusionJason ParisiKyle SchillerMarathon Fusion produces the world’s most valuable isotopes with compact, commercial fusion reactors. Founded by a team from SpaceX, Schmidt Futures and Princeton, Marathon is supported by $18m in funding and revenue across the US Department of Energy, the UK Atomic Energy Authority, and leading private investors. Company calculations show that power plants using its approach could generate roughly 5,000 kg of gold per year per gigawatt of output.
Mass MagneticsMatthew GrollEric SilverMass Magnetics is a YC-backed startup building high-performance permanent magnets domestically from recycled rare-earths. The founders previously built battery pilot-production lines and materials-science labs for NASA, Draper Labs, and MIT.
Mayo ClinicVera MucajVera Mucaj, PhD, is an EIR at Mayo Clinic, where she helps turn leading clinical science into new ventures. Previously, Vera was Datavant’s Chief Scientific Officer and employee #8. She led the life sciences product portfolio and founded the clinical trials business, which was adopted in over 250 trials by most top 20 pharma and biotech companies.
Merge LabsPradeep RameshMerge Labs is a research lab building higher bandwidth, less-invasive brain-computer interfaces that connect with neurons using molecules instead of electrodes, transmit and receive information using deep-reaching modalities like ultrasound, while avoiding implants into brain tissue. Merge Labs was co-founded by leading BCI researchers, Sam Altman, Alex Blania, and Sandro Herbig. OpenAI and Bain Capital led Merge's $250M seed round which also included investments from Interface Fund, Fifty Years, and Valve co-founder Gabe Newell.
Northwell HealthBrian S. KimDr. Brian S. Kim, MD, is Northwell Health’s Chief Biotech Officer. Northwell Health is New York's largest health system and employer, serving over 3M patients annually. Brian contributed to two FDA-approved treatments, authored more than 190 publications, holds multiple patents, and co-founded three biotech companies. He has been continuously funded by the NIH since 2011.
Radify MetalsDan BullardZach DetweilerAlex FisherRadify Metals is rebuilding a critical-minerals supply chain through the conversion of metal oxides into high-purity metal. The company has raised just under $3 million from Overture, Founders Inc., Mana Ventures, and Acequia Capital. Its modular hydrogen-plasma reactors transform rare-earth and other critical-mineral oxides directly into metal. Radify is building a flexible domestic metallization platform that could make critical-metal production faster, cleaner, and more resilient, directly targeting a supply chain in which China currently controls roughly 87% of global rare-earth refining capacity.
Retro BiosciencesYuuki HosokawaRetro Biosciences is a clinical-stage longevity company aiming to add ten healthy years to human life. Backed with a $180 million check from Sam Altman in 2022, it has since raised at a reported $1.8 billion valuation. Its lead oral program, RTR242, is designed to restore autophagy and entered Phase I testing in Austria in 2025.
Strand TherapeuticsRio BoothelloDan HartmanStrand Therapeutics is an MIT spinout building programmable mRNA medicines. Its total funding exceeds $250 million, including Regeneron Ventures, ICONIQ, Amgen Ventures, the family office of former J&J CEO Alex Gorsky, and Eli Lilly. The company combines targeted lipid nanoparticles, microRNA-responsive safety circuits, and self-replicating or circular RNA to address mRNA's central challenges of targeting, safety, and durability. Its lead IL-12 program, presented at the 2025 ASCO Annual Meeting, has shown early clinical activity in advanced solid tumors.
Xilio TherapeuticsOleg YerovXilio Therapeutics is a clinical-stage immuno-oncology company engineering cancer therapies to activate chiefly inside tumor microenvironments. Publicly traded on Nasdaq (XLO), Xilio has raised over $200M to date. In August 2026, the FDA cleared its IND for XTX501 as a potential foundational backbone therapy for solid tumors, with a Phase 1/2 trial starting in the second half of 2026.

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