IL1F9 Full-Length MS Protein Standard (NP_062564), Labeled with [U- 13C6, 15N4]-L-Arginine and [U- 13C6, 15N2]-L-Lysine, was produced in human 293 cells (HEK293) with fully chemically defined cell culture medium to obtain incorporation efficiency at Creative-Proteomics. 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. Two alternatively spliced transcript variants encoding different isoforms have been found for this gene.