BioEssays 7∕2013

Fuse and mix. In eukaryotes, SNARE‐mediated membrane fusion is vital for processes such as vesicle trafficking and secretion. It can be studied using vesicles tagged with different lipid‐mixing indicators (represented by the orange and green spheres on the cover). However, as Diao et al. discuss on pages 658–665 of this issue, simply relying on lipid‐mixing indicators is not enough. They point out that there is no direct correlation between lipid mixing and content mixing: Lipid mixing often occurs much earlier than content mixing or even without any content mixing at all. They therefore recommend that content‐mixing indicators are used in addition to, or in place of, lipid‐mixing indicators. Cover by Jiajie Diao et al.