This original research paper reported the isolation, expansion, and characterisation of human corneal endothelial cells (HCECs) in culture, in order to develop a cell therapy for corneal endothelial diseases, currently reliant on a very limited donor supply. Furthermore, a set of 4 cell surface markers were identified that could be used to distinguish canonical HCECs from those that have undergone endothelial-mesenchymal transition into fibroblasts. Currently no such marker exists. Cells that are positive for one of these markers, CD58, also have higher TEER readings, suggesting that they have higher junctional resistance (i.e. functionality). Therefore these novel HCEC markers have the potential to be used as a quality control mechanism for future cell therapies, to ensure only functional canonical cells are transplanted. The results will have significant impact on the field of corneal endothelial cell therapy. Several specific comments are as below:

1. The title conveyed the main finding of the study very well, which is the identification of novel markers for HCECs. Please revise the aims statements in the abstract and the end of the introductory sections to include the identification of novel markers as one of the aims.
2. Please clarify whether ethics approval was obtained from an institutional board to use donor corneas for research.
3. Please revise the statistical analysis section to include the methodology used to analyse results presented in Figure 1J, Figure 2C, and the microarray data.