IL1R1 encodes the type 1 interleukin-1 receptor, which serves as the primary receptor for IL-1α, IL-1β, and the IL-1 receptor antagonist (IL1RN) 1. The receptor functions by associating with the co-receptor IL1RAP to form a high-affinity signaling complex that activates NF-κB, MAPK, and other inflammatory pathways through recruitment of adapter molecules including MYD88 and IRAK proteins. IL1R1 expression varies significantly across different cell types and disease contexts. In cancer, IL1R1+ fibroblasts promote tumor growth and immune suppression in colorectal cancer, with IL1R1 knockout reducing tumor progression 2. The receptor shows distinct expression patterns in inflammatory skin diseases, with higher IL1R1 levels in hidradenitis suppurativa T17 cells compared to psoriasis, suggesting disease-specific IL-1β-driven activation pathways 3. IL1R1 signaling contributes to pancreatic inflammation and cancer development through MAPK pathway activation 1, and plays roles in bronchiolar disease by mediating mucin production in response to IL-1β 4. In breast cancer, IL1R1+ neutrophils participate in ferroptosis-mediated immunosuppression and chemoresistance 5. The receptor has been identified as a core gene in intervertebral disc degeneration, highlighting its broader role in inflammatory pathologies 6.