Anti-DER4 antibodies are protein reagents that detect specific antigens. The DER4 antigen is another term for the human protein interleukin 1 receptor like 1, encoded by the IL1RL1 gene. The protein is a known receptor for interleukin-33 (IL-33); signaling requires association of the coreceptor IL1RAP. Canonically, it has an amino acid length of 556 residues and a mass of 63.4 kilodaltons. Its subcellular localization is in the cell membrane and is secreted. It is reported to be highly expressed in the kidney, lung, placenta, stomach, skeletal muscle, colon and small intestine. The DER4 protein is a member of the Interleukin-1 receptor protein family. Other alias names for DER4 include FIT-1 and IL33R. Some DER4 antibodies may have been used in research and have associated citations. Western Blot is a widely used application for these antibodies. ELISA and Immunohistochemistry are also common applications.