Gabriel Tremblay

Gabriel Levesque-Tremblay is the CEO and co-founder of HexemBio, a New York and Berkeley biotech building what it calls the first scalable blood stem cell rejuvenation therapy. A synthetic biologist with a PhD from UBC and a postdoc at UC Berkeley, he is a two-time founder and Y Combinator alumnus who earlier co-founded the cultivated-meat startup Orbillion Bio. At HexemBio he turns aged hematopoietic stem cells young again by passing them through a recreated embryonic 'Synthetic Yolk Sac' before returning them by IV. The company closed a $10.4M seed round led by Draper Associates in April 2026 and is targeting first-in-human trials by 2027.