Enables interleukin-1 receptor binding activity. Predicted to be involved in several processes, including interleukin-33-mediated signaling pathway; positive regulation of cytokine production; and regulation of synapse assembly. Predicted to act upstream of or within cytokine-mediated signaling pathway and positive regulation of dendrite development. Located in cytoplasm. Part of protein-containing complex. Orthologous to human IL1RAP (interleukin 1 receptor accessory protein). [provided by Alliance of Genome Resources, Apr 2022]