Interleukin 21 (IL-21), encoded by the IL21 gene, is a member of the common gamma-chain family of cytokines with immunomodulatory activity. IL-21 plays a role in innate and adaptive immune responses by inducing the differentiation, proliferation and activity of a variety of target cells including macrophages, natural killer cells, B cells and cytotoxic T cells. IL-21 is expressed on activated human CD4+ T cells but not in most other tissues. IL21 is considered a key signal that triggers the proliferation of chronic lymphocytic leukemia cells. Dysregulation of IL-21 is associated with a variety of immune-mediated diseases, including lupus, psoriasis, and chronic inflammatory diseases. Additionally, IL-21 was found to be produced by Hodgkin's lymphoma (HL) cancer cells, suggesting that IL-21 may be a potential treatment or a possible test for HL. This product is designed as a tool for the delivery and expression of human IL21 mRNA for research. The product leverages the lipid nanoparticle (LNP) technology platform for simple and efficient delivery of hIL21 mRNA to a variety of mammalian cells in vitro and in vivo. The LNPs used are formulated with SM-102, DSPC, cholesterol and DMG-PEG2000 at an optimal molar concentration for a high rate of encapsulation and efficient mRNA delivery. The IL21 protein is about 18 kD and consists of 162 amino acids. The GenPept accession number is NP_068575.