WPBs: making a mark and leaving a trail.

In this issue of , Holthenrich et al used a proximity labeling approach to pull, from out of the crowded intracellular milieu, proteins that specifically interact with Weibel-Palade bodies (WPBs). From the resulting catalog of proteins, the authors identified Munc13-2 as a novel WPB-associated SNARE-interacting protein that positively regulates hormone-evoked WPB exocytosis.