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 594
Alexa Fluor™ 594 (AF594, Alexa 594) has an excitation peak at 590 nm and an emission peak at 617 nm, and is spectrally similar to Texas Red (ThermoFisher Scientific), DyLight™ 594 (ThermoFisher Scientific), iFluor® 594 (ATT Bioquest) and iFluor® 610 (ATT Bioquest), CF®594 (Biotium), and ATTO 594 (ATTO-TEC). Alexa 594 is commonly used for flow cytometry,fluorescence microscopy and super-resolution microscopy. It is very bright, photostable, and pH insensitive.