About IL-31
IL31, which is made principally by activated Th2-type T cells, interacts with a heterodimeric receptor consisting of IL31RA (MIM 609510) and OSMR (MIM 601743) that is constitutively expressed on epithelial cells and keratinocytes. IL31 may be involved in the promotion of allergic skin disorders and in regulating other allergic diseases, such as asthma (Dillon et al., 2004 [PubMed 15184896]).[supplied by OMIM, Mar 2008]

About Alexa Fluor 555
Alexa Fluor™ 555 (AF555, Alexa 555) has an excitation peak at 555 nm and an emission peak at 565 nm, and is spectrally similar to Cy®3 (GE Healthcare), TRITC, iFluor® 555 (ATT Bioquest) and iFluor® 560 (ATT Bioquest). Many flow cytometers are equipped with 532nm lasers, so while Alexa 555 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.