Scientists always say they are working at the frontier of knowledge (we usually increase the self-praise by calling it the 'cutting edge'). But that's a trivial way to express vested interest, really, because things that are known are not being explored by science, so in a sense it's the definition of science to be studying what we don't already know.
On the other hand, what we do know is rather remarkable when you think of the complexity and elusiveness of Nature. DNA and molecular interactions can't be seen the way ordinary objects and interactions can. We are dealing with very large numbers of very small particles interacting in very many ways. In fact, everything genetic, genomic, and cellular turns out to be related to everything else (to oversimplify a bit).
Yet, almost no matter what you may ask about, Googling will reveal a substantial, usually rather huge, literature on the subject. Nonetheless, the subject isn't closed, the problem not 'solved', and the complexities are manifest.
One can ask, for example, about the genetic involvement or cause of a disease, even a rare disease of variable or multiple symptoms, and find that something is known about its molecular cause.
It may be a neurotransmitter problem, or an energy metabolism one, or a developmental anomaly, etc. Variants at some gene(s) are usually known that 'cause', or at least are involved with, the trait. Yet if you dig deeper, the stories are not very tight. Prediction from gene to trait is, with some usually-rare exceptions, not that strong, and often treatment, and almost always prevention, remain elusive. Is this because we just haven't gotten around to figuring these things out, or because we don't know how to know them? Do we need a new way to think about complexity?
It's remarkable in many ways that we know anything about these problems, even if it's equally sobering how difficult it is to truly understand them. It's a combined testimony to the power of research methods, the army of investigators employing them, but also the way in which these methods reveal facts as well as uncertainties. Often the tag line in papers or the news is about what we know, and what we don't know is kept quieter. Some believe that with time and resources, our methods and technology will finish the job. Others would say that if we believe that, we are not really accepting and dealing with complexity head-on as we should. And, as we wrote yesterday, it's always sobering to realize that the assumptions we base our knowledge on may themselves be faulty--but we never know at the time which ones they are or what's wrong with them.
There's probably no one way to view this. But, still, it's amazing how much we do know about things that are so little and complex.