Exo2 is a secretion inhibitor that hinders the trafficking of Shiga toxin from endosomes to the trans-Golgi network. It inhibits the exit of secretory cargo from the endoplasmic reticulum (ER) and disrupts the Golgi apparatus. Notably, Exo2 does not impact the morphology of the trans-Golgi network (TGN). Additionally, Exo2 has the ability to induce calcium-dependent exocytosis in permeabilized adrenal chromaffin cells (1) (2).