The short answer here is yes. We're constantly working to get more complete models, but surprisingly big effects can come from surprisingly small pieces of the puzzle. We still don't even really understand how Tylenol/Paracetamol/Acetaminophen works!

A great example of the gap between our current models and what would be sufficient comes from the COX-2 inhibitors (Vioxx/Celebrex). Ibuprofin (Motrin/Advil) and other NSAIDs modulate both COX-1 and COX-2 receptors in the body to reduce inflammation, but inhibiting COX-1 also causes stomach damage. The early COX-2-specific inhibitors were designed from the ground up using our best models, which were thought to be well-understood. Unfortunately, after several years on the market, it was discovered that this also came with a large increased risk of heart attacks and strokes.

The body just has so so many moving pieces, and while we're getting better, it's going to be some time before we are able to base these studies entirely on theory, and when we get there we'll be able to skip the mice entirely!