From Erik Foxcroft, St Albans, Hertfordshire, UK
If Gou Young Koh and his colleagues want to find out if massaging the faces of people helps flush waste from their brains, as they found it does in mice, they could look for differences between the brains of deceased men who shaved every day and those who had well-grown beards. While the results would be sex-biased, and may be easier to do with certain nationalities, they could provide a quick preliminary check as to whether this works(14 June, p 11).
