Maxime Feyeux was one of the first PhD students to work with pluripotent stem cells in France and on their applications in neurology, at the Institute for Stem Cell Therapy and Exploration of Monogenic Diseases (i-Stem). During his PhD thesis, he authored in 2008 a seminal paper on pluripotent stem cells' genomic integrity, focusing on the selection of the oncogenic 20q11 mutation over prolonged culture. Maxime Feyeux continued his research in the field of PSCs at the University of Geneva, modeling Huntington's disease genetic dysregulation and investigating PSC-based therapeutics approaches. In 2014, he met Kévin Alessandri, a biophysicist specialized in cell encapsulation microfluidics. Together, they invented C-StemTM, a biomimetic technology allowing for the mass production of induced pluripotent stem cells, and their differentiation into ready-to-transplant microtissues, with unprecedented scalability and cell quality. In 2018, a few months before incorporating TreeFrog Therapeutics, Feyeux and Alessandri performed the world-first transplantation of iPS-derived mature dopaminergic neurons into an animal model of Parkinson’s disease, demonstrating full motor-function recovery occurring faster than with standard protocols.