Anti-IL-33 antibodies are used in antigen-specific immunodetection in biological samples. The target IL-33 is a known alias name of the protein interleukin 33, encoded by the IL33 gene in humans. This 270-amino acid residue protein is a reported to be a cytokine that binds to and signals through the IL1RL1/ST2 receptor which in turn activates NF-kappa-B and MAPK signaling pathways in target cells. It is localized to the nucleus, cytoplasmic vesicles, cytoplasm, and is secreted of the cell and features cleaved post-translational modifications. In terms of tissue expression, it is notably expressed at high level in high endothelial venules found in tonsils, Peyer patches and mesenteric lymph nodes. Other synonyms for IL-33 include DVS27-related protein, interleukin-1 family member 11, and nuclear factor for high endothelial venules. Over 320 citations in the literature describe the use of IL-33 antibodies in research. ELISA is a widely used application for these antibodies. In addition, Western Blot is also a common application.