Purity: > 95% by SDS - PAGE Format: Liquid. Phosphate buffer saline (pH7.4). IL-21, also known as Interleukin-21, is a T-helper cytokine that regulates humoral immunity and cell-mediated anti-tumor responses. It has broad immunoregulatory activity and can modulate both humoral and cell-mediated responses. It is important in the regulation of haematopoiesis and immune responses, and can influence lymphocyte development. It is produced by activated T cell, and it influences proliferation of T and B cells and cytolytic activity of natural killer cells. It may be a critical factor in the control of persistent viral infections. It has a potential predicating significance for survival Time in patients in the development of sporadic CRC. It binds to the IL-21R and can activate janus kinase JAK1, JAK3, STAT1, and STAT3 in EDgamma-16 cells. Recombinant human IL-21, was expressed in E. coli and purified by using conventional chromatography techniques.