Interesting but is so poorly written that it is very difficult to decipher, not even a summary or discussion section.

Zebrafish have retinas very similar to mammals. For whatever reasons, they are able to regenerate their retinas when injured, while we mammals can't.

Scientists hypothesized that the presence of a certain protein is the reason why we can't, and they experimented with mice to see if blocking the protein would allow them to regenerate their retinas. It did.