RNASE3, also known as Ribonuclease RNase A family 3, located in the eosinophil primary matrix. It 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. It is a potent cytotoxic protein capable of killing cells of guinea pig tracheal epithelium, mammalian leukemia, epidermis carcinoma, and breast carcinoma, as well as non-mammalian cells such as parasites, bacteria, and viruses. Recombinant human RNASE3 protein, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.