Nexinhib20 is a specific Rab27a-JFC1 interaction inhibitor with a calculated IC 50 of 2.6 μM. Nexinhib20 significantly inhibits superoxide anion production. Nexinhib20 efficiently decreases exocytosis of azurophilic granules in neutrophils stimulated with fMLP, GM-CSF or both. Nexinhib20 has a significant anti-inflammatory activity.