When you have a research job you are always finding out new things, the whole idea is to find out something new, or do a new experiment that no one has done before. Sometimes scientists go over other work if they think that it wasn’t done correctly or might have given incorrect results, but they usually try to add something new as well. You then publish it so that other scientists can read about it. If you go over something that has been done before and don’t add anything new to it, then the companies that publish things won’t accept your work to be published.
Yes – pretty much everything I do has never been done before. Similar things might have been done for other diseases or in other areas, but there is always more information needed and more new research that needs to be done, so I do find out new things!
The whole idea of being a research is finding a way to increase human knowledge. Even if you optimize something that someone else has done or find a similar but better technique – that still counts as research.
Of course, the thrill is always to find something fundamentally different that will change our understanding!