About CD4
This gene encodes the CD4 membrane glycoprotein of T lymphocytes. The CD4 antigen acts as a coreceptor with the T-cell receptor on the T lymphocyte to recognize antigens displayed by an antigen presenting cell in the context of class II MHC molecules. The CD4 antigen is also a primary receptor for entry of the human immunodeficiency virus through interactions with the HIV Env gp120 subunit. This gene is expressed not only in T lymphocytes, but also in B cells, macrophages, granulocytes, as well as in various regions of the brain. The protein functions to initiate or augment the early phase of T-cell activation, and may function as an important mediator of indirect neuronal damage in infectious and immune-mediated diseases of the central nervous system. Multiple alternatively spliced transcript variants encoding different isoforms have been identified in this gene. [provided by RefSeq, May 2020]

About Alexa Fluor 532
Alexa Fluor™ 532 (AF532, Alexa 532) has an excitation peak at 532 nm and an emission peak at 554 nm, and is spectrally similar to Cy®3 (GE Healthcare), TRITC, iFluor® 514 (ATT Bioquest) and iFluor® 546 (ATT Bioquest). Many flow cytometers are equipped with 532nm lasers, so while Alexa 532 can be used for flow cytometry, PE is more commonly used due to its brightness and spectral characteristics. This dye is commonly used for fluorescence microscopy applications.