Purity: > 85% by SDS - PAGE Format: Liquid. In Phosphate Buffered Saline (pH 7.4) containing 20% glycerol.. IL21, also known as interleukin-21 isoform 1, is a T-helper cytokine that regulates humoral immunity and cell-mediated anti-tumour 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 cells, 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 IL21, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.