The domain within your query sequence starts at position 28 and ends at position 185; the E-value for the IL23 domain shown below is 2.4e-98.

PDWAQCQQLSRNLCMLAWNAHAPAGHMNLLREEEDEETKNNVPRIQCEDGCDPQGLKDNS
QFCLQRIRQGLAFYKHLLDSDIFKGEPALLPDSPMEQLHTSLLGLSQLLQPEDHPRETQQ
MPSLSSSQQWQRPLLRSKILRSLQAFLAIAARVFAHGA

IL23

 IL23
PFAM accession number:PF16649
Interpro abstract (IPR010831):

This entry represents interleukin-23 subunit alpha, IL-23A (also known as Interleukin-23 subunit p19) associates with IL-12B to form the IL-23 interleukin, a heterodimeric cytokine which functions in innate and adaptive immunity [ (PUBMED:11114383) ]. IL-23 may constitute with IL-17 an acute response to infection in peripheral tissues. IL-23 binds to a heterodimeric receptor complex composed of IL12RB1 and IL23R, activates the Jak-Stat signaling cascade, stimulates memory rather than naive T-cells and promotes production of proinflammatory cytokines. IL-23 induces autoimmune inflammation and thus may be responsible for autoimmune inflammatory diseases and may be important for tumorigenesis [ (PUBMED:16424222) ]. Similar to IL-12, human IL-23 stimulates IFN-gamma production and proliferation in PHA blast T cells, as well as in CD45RO (memory) T cells [ (PUBMED:11114383) ].

GO process:immune response (GO:0006955)
GO component:extracellular region (GO:0005576)
GO function:cytokine activity (GO:0005125)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry IL23