ER-endosome contacts master the ins and outs of secretory endosomes.

What defines whether an endosome follows the degradative pathway or fuses with the plasma membrane to release exosomes? In this issue of JCB, Fredrik Verweij and colleagues (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202112032) demonstrate how secretory endosomes are guided by ER-endosome contacts to take a cellular detour and several identity transitions for efficient exosome release.