RPS18 (ribosomal protein S18) is a structural component of the small ribosomal subunit involved in cytoplasmic protein synthesis. As part of the 40S ribosomal subunit, RPS18 functions in translation initiation and elongation within the cytosol 1. Beyond its canonical ribosomal role, RPS18 exhibits context-dependent regulatory functions in disease pathways. In pancreatic adenocarcinoma, IRF7-regulated RPS18 is transferred via M1 macrophage-derived exosomes to cancer cells, where it suppresses lipid metabolism, cell proliferation, and migration while promoting apoptosis, suggesting a tumor-inhibitory function 2. Conversely, in Kaposi's sarcoma, RPS18 downregulation promotes cellular proliferation and angiogenesis, indicating tissue-specific roles 3. RPS18 serves as a reliable reference gene for quantitative PCR studies in cancer and leukemia research due to stable expression 14. During viral infection, RPS18 is recruited by the DDX21 helicase to viral dsRNA, enhancing viral protein synthesis and promoting Classic Swine Fever Virus replication 5. Genetically, RPS18 variants are causally associated with sepsis-related acute respiratory distress syndrome and represent a potential druggable target 6. These findings demonstrate that RPS18 functions beyond basic translation, participating in intercellular communication, viral pathogenesis, and disease progression.