But, Wyss - Coray says, «Alzheimer's patients don't want to wait until the exact mode of action is discovered.» (scientificamerican.com)
The exact mode of action in MS is not yet known. (sciencedaily.com)
Well, it's been true that there's been plenty of dispute about the exact mode of Lucy's locomotion: was she completely bipedal, or partly arboreal? (talkorigins.org)