The function of Ensembl gene identifier ENSG00000115594 (IL1R1, interleukin 1 receptor type 1) is as follows. Receptor for IL1A, IL1B and IL1RN (PubMed:2950091, PubMed:37315560). After binding to interleukin-1 associates with the coreceptor IL1RAP to form the high affinity interleukin-1 receptor complex which mediates interleukin-1-dependent activation of NF-kappa- B, MAPK and other pathways. Signaling involves the recruitment of adapter molecules such as TOLLIP, MYD88, and IRAK1 or IRAK2 via the respective TIR domains of the receptor/coreceptor subunits. Binds ligands with comparable affinity and binding of antagonist IL1RN prevents association with IL1RAP to form a signaling complex. Involved in IL1B-mediated costimulation of IFNG production from T-helper 1 (Th1) cells (PubMed:10653850). {ECO:0000269|PubMed:10653850, ECO:0000269|PubMed:10671496, ECO:0000269|PubMed:2950091, ECO:0000269|PubMed:37315560}.