Inferred from mouse :
Signal transducer and activator of transcription 3 (STAT3) binds tyrosine residues of the Interleukin-23 receptor (IL23R) after cytokine-receptor interaction (Dumoutier et al. 2009, Floss et al. 2013). This is a black box event because STAT3 binding as a consequence of Interleukin-23 stimulation has not been directly demonstrated. IL23R can also bind STAT4, this alternative binding is not represented here only because the evidence for STAT3 binding is inferred from mouse/human chimeras while STAT4 binding evidence was obtained with human protein data.