After a relatively tough year for stem cell companies on the public markets, they finally had something to cheer about – a regulatory milestone that could pave the way for a number of future approvals of stem cell therapies currently in late-stage clinical trials. The breakthrough event was Health Canada's approval of Prochymal (remestemcel-L), Osiris Therapeutics Inc.'s allogeneic stem cell treatment for graft-vs.-host disease (GvHD) in children.