Professor Thomas Yorio's name is being deleted from the author list by his request. He did not feel his contribution was sufficient for authorship.

According to Van Bergen et al. [1], RGC-5 cells are likely to be mouse origin, not rat origin as mentioned in our original paper. Moreover, RGC-5 cells have many properties of the 661 W cell line (mouse photoreceptor blastoma cells). Thus, the characteristics of RGC-5 cells are closer to neuronal precursor cells, rather than retinal ganglion cells [2].