這個基因編碼的蛋白質是一種主要由單核細胞產生的細胞因子，在一定程度上由淋巴細胞產生。這種細胞因子在免疫調節和炎癥中有多種作用。下調巨噬細胞th1細胞因子、mhcⅡ類ags和共刺激分子的表達。它還可以增強b細胞的存活、增殖和抗體的產生。該細胞因子可阻斷NF-卡帕B活性，參與JAK-STAT信號通路的調節。小鼠的基因敲除研究表明，這種細胞因子在腸道中起著重要的免疫調節作用。該基因的突變與hiv-1感染和類風濕關節炎的易感性增加有關。
The protein encoded by this gene is a cytokine produced primarily by monocytes and to a lesser extent by lymphocytes. This cytokine has pleiotropic effects in immunoregulation and inflammation. It down-regulates the expression of Th1 cytokines, MHC class II Ags, and costimulatory molecules on macrophages. It also enhances B cell survival, proliferation, and antibody production. This cytokine can block NF-kappa B activity, and is involved in the regulation of the JAK-STAT signaling pathway. Knockout studies in mice suggested the function of this cytokine as an essential immunoregulator in the intestinal tract. Mutations in this gene are associated with an increased susceptibility to HIV-1 infection and rheumatoid arthritis.[provided by RefSeq, May 2011]