These EVs contain eosinophil-derived enzymes including eosinophil peroxidase (EPO), major basic protein (MBP), and eosinophil cationic protein (ECP) and have a role in BA.EVs from eosinophils of patients with BA act in an autocrine manner and can be distinguished from EVs from eosinophils of healthy subjects. The gene discussed is EPX; the disease is breast angiosarcoma.