Core Viewpoint - The study highlights the role of gut microbiota, specifically the metabolite urocanic acid (UCA), in enhancing the efficacy of cancer immunotherapy when combined with tyrosine kinase inhibitors (TKIs) [3][8][11]. Group 1: Research Findings - The research demonstrates that TKIs increase the abundance of the gut bacterium Muribaculum gordoncarteri and its metabolite UCA, which enhances the response to immune checkpoint blockade (ICB) therapy [8][9]. - UCA interacts with IκBα to inhibit NF-κB activation in endothelial cells, thereby reducing the recruitment of myeloid-derived suppressor cells (MDSCs) mediated by CXCL1 [9][11]. - Higher levels of UCA and Muribaculum gordoncarteri are found in the feces of patients who respond to ICB therapy compared to non-responders, suggesting their potential as predictive biomarkers for treatment response [8][9][11]. Group 2: Implications for Cancer Treatment - The findings indicate that the interaction between TKIs and gut microbiota could be a crucial factor in improving cancer treatment outcomes, particularly for patients who currently do not respond well to existing therapies [7][9]. - Understanding the mechanisms by which UCA enhances ICB therapy could lead to new strategies for increasing the effectiveness of cancer immunotherapy [3][11].