The Front Cover illustrates the molecular structures of coumarin-caged ryanodine receptor (RyR) agonists and blockers. Photo-irradiation of a (6-bromo-7-hydroxycoumarin-4-yl)methyl (Bhc)-caged agonist released the active form, activated RyRs, and promoted Ca2+ release from the endoplasmic reticulum in mammalian cells. The photoreactivity of the caged RyR probes by 405 nm light was masked by the enzyme substrates, allowing cell-type-selective, enzyme gene-directed delivery of the caged RyR probes. More information can be found in the Research Article by A. Yokoyama, H. Aoki, T. Furuta et al. (DOI 10.1002/cptc.202400140).