Cover picture: Rhod-2 fluorescence in response to 10 mM caffeine in HEK293 cells transfected with pore mutants D4899A (upper panels) and D4917A (lower panels) of the skeletal muscle Ca²⁺  release channel (RyR1). Cells showing an increase in pseudocolor value with caffeine are indicated by an arrow. See the article by Gao et al. on p. 828.