The hitchhiker's guide to the chemical-biological galaxy.

We are used to considering chemical and biological spaces as two different entities; although they represent a more-interconnected world, in fact they represent a Yin-Yang concept in drug discovery. Chemical-biological space is as vast as the universe and, as Douglas Adams famously said, 'Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is'. However, many researchers are convinced that it is not so infinite, and are designing computational and experimental tools to help identify and explore all possible chemical-biological space. Here, we provide an analysis of their approaches and discuss possible future research studies.