QS11 is a potent and selective inhibitor of ARFGAP1, a GTPase-activating protein crucial for regulating Arf1-mediated intracellular vesicle trafficking and Golgi apparatus function. By inhibiting ARFGAP1 (IC₅₀ = 110 nM), QS11 disrupts endocytic recycling and secretory pathways, impacting cell migration, invasion, and intracellular signaling. It is widely used in cell biology research to study these processes and in cancer studies, where it demonstrates potential to suppress tumor cell motility, proliferation, and metastasis. Ongoing research explores QS11's mechanisms to advance therapeutic strategies for diseases involving dysregulated trafficking, such as cancer.