The FDA Critical Path Initiative directs a more intelligent approach for development of drugs that effect the brain and behavior. It must start with gene activation in cells of hormone-secreting tissue in the brain, which is the most important organ of any organ system involved in behavior. The potential for the use of knowledge gleaned from the molecular biology of olfaction increases each time a report links odors to behavior — as is the case with food odors and social odors in all species from microbes to man. What’s happening now appears to be an attempt to get back to the basic principles of biology and levels of biological organization across species. I’m not sure where researchers first strayed from the gene, cell, tissue, organ, organ-system pathway, but I am happy to see evidence that research may get back on the path that directly links sensory input to brain function and behavior.