About IL-21
This gene encodes a member of the common-gamma chain family of cytokines with immunoregulatory activity. The encoded protein plays a role in both the innate and adaptive immune responses by inducing the differentiation, proliferation and activity of multiple target cells including macrophages, natural killer cells, B cells and cytotoxic T cells. Dysregulation of this gene plays a role in multiple immune-mediated diseases including lupus, psoriasis and chronic inflammatory diseases. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Dec 2011]

About Alexa Fluor 750
Alexa Fluor™ 750 (AF750, Alexa 750) has an excitation peak at 749 nm and an emission peak at 775 nm, and is spetrally similar to Cy®7 (GE Healthcare), APC-Fire™ 750 (BioLegend), CF®®750 (Biotium), DyLight™ 750 (ThermoFisher Scientific), iFluor® 750 (ATT Bioquest) and iFluor® 790 (ATT Bioquest). Alexa 750 is often used as a tandem fluorophore in flow cytometry or used on its own in fluorescence microscopy, in-vivo fluorescence microscopy or super-resolution microscopy applications.