Eosinophil Cationic Protein (ECP) also known as ribonuclease 3 is a basic protein located in the eosinophil primary matrix. In humans, the eosinophil cationic protein is encoded by the RNASE3 gene. ECP is released during degranulation of eosinophils. This protein is related to inflammation and asthma because in these cases, there are increased levels of ECP in the body. There are three glycosolated forms of ECP and consequently ECP has a range of molecular weights from 18-22 kDa