Il18r1, the interleukin 18 receptor 1, is a key component of the IL-18 signaling pathway. IL-18, a member of the IL-1 cytokine superfamily, is an important regulator of innate and acquired immune responses [2,4]. Il18r1 is part of the IL-18 receptor complex, which also includes a signaling chain. Activation of this complex recruits kinases and factors that phosphorylate and activate NF-κB, influencing the expression of genes related to cytokines, chemokines, and immune-related molecules [4].

In a mouse model of liver fibrosis induced by HSC-specific NLRP3 overactivation, Il18r1-deficient mice had reduced liver fibrosis. Single cell RNA sequencing showed that an immunoregulatory subset of murine hepatic stellate cells (HSCs) highly expresses Il18 and Il18r1, and treatment of cultured primary murine HSC with recombinant mouse IL-18 accelerated their transdifferentiation into myofibroblasts. This indicates that IL-18 signaling through Il18r1 promotes HSC activation and liver fibrosis [3]. In lung squamous cell carcinoma, overexpression of Il18r1 inhibited the proliferation, migration, and invasion of cancer cells, suggesting its role in suppressing cancer progression [1].

In conclusion, Il18r1 is crucial in the IL-18 signaling pathway, playing a significant role in immune-related biological processes. Mouse models, such as Il18r1-deficient mice in liver fibrosis research, have revealed its importance in disease-related cellular processes. These findings suggest that Il18r1 could be a potential target for treating liver fibrosis and may have implications for understanding and treating other diseases like lung squamous cell carcinoma.