Interleukin-1 family member 9 is a protein that in humans is encoded by the IL1F9 gene.

The protein encoded by this gene is a member of the interleukin 1 cytokine family. The activity of this cytokine is mediated by interleukin 1 receptor-like 2 (IL1RL2/IL1R-rp2), and is specifically inhibited by interleukin 1 family, member 5 (IL1F5/IL-1 delta). Interferon-gamma, tumor necrosis factor-alpha and interleukin 1, beta (IL1B) are reported to stimulate the expression of this cytokine in keratinocytes. The expression of this cytokine in keratinocytes can also be induced by a contact hypersensitivity reaction or herpes simplex virus infection. This gene and eight other interleukin 1 family genes form a cytokine gene cluster on chromosome 2. [provided by RefSeq, Jul 2008]. Publication Note: This RefSeq record includes a subset of the publications that are available for this gene. Please see the Gene record to access additional publications.
Function: Function as an agonist of NF-kappa B activation through the orphan IL-1-receptor-related protein 2. Could constitute part of an independent signaling system analogous to interleukin-1 alpha (IL-1A), beta (IL-1B) receptor agonist and interleukin-1 receptor type I (IL-1R1), that is present in epithelial barriers and takes part in local inflammatory response.