Description_x000D_ General description_x000D_ Interleukin 23 subunit α (IL23A) gene with 4 exons, spanning 1531bp of genomic DNA, is mapped to human chromosome 12q13.2. The gene codes for a 19kDa cytokine, p19. The protein consists of a signal peptide and mature peptide composed of four α helices._x000D_ This gene encodes a subunit of the heterodimeric cytokine interleukin 23 (IL23). IL23 is composed of this protein and the p40 subunit of interleukin 12 (IL12B). The receptor of IL23 is formed by the β1 subunit of IL12 (IL12RB1) and an IL23 specific subunit, IL23R. Both IL23 and IL12 can activate the transcription activator STAT4, and stimulate the production of interferon-γ(IFNG). In contrast to IL12, which acts mainly on naive CD4+ T cells, IL23 preferentially acts on memory CD4+ T cells. (provided by RefSeq)_x000D_ Immunogen_x000D_ IL23A (NP_057668.1, 1 a.a. ~ 189 a.a) full-length human protein._x000D_ Sequence_x000D_ MLGSRAVMLLLLLPWTAQGRAVPGGSSPAWTQCQQLSQKLCTLAWSAHPLVGHMDLREEGDEETTNDVPHIQCGDGCDPQGLRDNSQFCLQRIHQGLIFYEKLLGSDIFTGEPSLLPDSPVGQLHASLLGLSQLLQPEGHHWETQQIPSLSPSQPWQRLLLRFKILRSLQAFVAVAARVFAHGAATLSP_x000D_ Physical form_x000D_ Solution in phosphate buffered saline, pH 7.4_x000D_ Biochem/physiol Actions_x000D_ Interleukin 23 subunit α (IL23A) plays a vital role downstream of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway, that transduces signals for cell proliferation, differentiation, cell migration and apoptosis. Elevated expression of IL23A has been observed in meibomian cell carcinoma (MCC). Mutation in the gene increases the risk of susceptibility to psoriatic arthritis (PsA) as well as psoriasis.