**Acknowledgements**

MG holds a Canada Research Chair Tier 1 in Biomaterials and Stem Cells in Ophthalmology and the Caroline Durand Foundation Chair for Stem Cell Therapy in the Eye. Work done in the Griffith lab has been supported by grants from FRQS, CIHR, NSERC, and the Stem Cell network in Canada, and previous funding from the Swedish Research Council and Vinnova in Sweden.
