Interleukin-4 receptor alpha subunit (IL4R) and Interleukin-13 receptor subunit alpha 1 (IL13RA1) are phosphorylated on tyrosines in response to Interleukin-13 (IL13) in human blood monocytes (Roy et al. 2002, Bhattacharjee et al. 2013). The associated Janus-kinase (JAK) family kinases JAK2 and TYK2 are also phosphorylated (Roy & Cathcart 1998, Bhattacharjee et al. 2013). Although JAK1 binds to IL4R in response to IL13, it does not appear to be phosphorylated in response to IL13 (Roy & Cathcart 1998, Bhattacharjee et al. 2013).