EPX, eosinophil peroxidase, is an antimycobacterial protein that localizes to cytoplasmic granules of eosinophils and recruits bromide to generate a halogenating oxidant. EPX dependent generation of hypobromous acid causes damage to tissue during inflammatory conditions that include asthma, allergies,cancer and parasitic/helminthic infections. EPX is a major enzyme present in eosinophils and upon degranulation, becomes released into the airways of asthmatics. As a result of its cationic nature and its ability to catalyze the formation of highly toxic oxidants, EPX can induce lung injury in a JNK dependent manner.