David Grayzel is a physician-turned-venture capitalist at Atlas Venture who repeatedly co-founds and takes on CEO or chair roles at the biotech companies he backs, rather than staying purely on the investing side like most VCs. He specializes in immune system therapeutics and has co-founded multiple companies in areas like autoimmunity and oncology, including Surface Oncology, Q32 Bio, and Comanche Biopharma. David Grayzel is a physician-turned-venture capitalist at Atlas Venture who repeatedly co-founds and takes on CEO or chair roles at the biotech companies he backs, rather than staying purely on the investing side like most VCs. He specializes in immune system therapeutics and has co-founded multiple companies in areas like autoimmunity and oncology, including Surface Oncology, Q32 Bio, and Comanche Biopharma.