ECP is a 160 amino acid potent cytotoxic secretory protein that belongs to the pancreatic ribonuclease family. ECP localizes to the granule matrix of the eosinophil and is involved in the immune response system. ECP is a cytotoxin, neurotoxin and helminthotoxin that is secreted by activated human eosinophils. ECP exhibits anti-parasitic, antibacterial and ribonucleolytic activities. It has been suggested that ECP induces the neurotoxic effect known as the Gordon phenomenon, a syndrome manifested by ataxia, muscular rigidity, paralysis, and tremor that may lead to death. ECP is considered a marker of eosinophilic inflammation and high levels have been found in cases of active asthma and other allergic diseases