Cover Caption

About the cover: Amide backbone ribbon and space filling diagram of a human acetylcholinesterase subunit showing nonsynonymous and synonymous SNPs as yellow and blue side chains studied in relation to catalytic activity and general cardiovascular parameters. The active center serine side chain is white and the turquoise space filling residues are sites of glycosylation. Individual SNPs are mapped in Fig. 1 and three-dimensional structure is shown in Fig. 7 of Valle et al., on page 125 of this issue.