CCDC18-AS1 (coiled-coil domain containing 18 antisense RNA 1) is a long non-coding RNA that functions primarily as an oncogenic regulator across multiple cancer types. The lncRNA promotes tumor progression through competitive endogenous RNA (ceRNA) mechanisms, where it acts as a molecular sponge for tumor-suppressive microRNAs 12. In gastric cancer, CCDC18-AS1 directly binds to miR-214-3p, inhibiting its tumor-suppressive function and promoting proliferation, migration, and invasion through regulation of apoptosis-related proteins including Bax, Bcl-2, P21, and Cyclin B1 1. Similarly, in hepatocellular carcinoma, CCDC18-AS1 participates in ceRNA networks involving let-7c-5p and EZH2 2. The lncRNA demonstrates significant clinical relevance as a prognostic biomarker, with high expression correlating with poor survival outcomes in gastric cancer and serving as an independent risk factor 1. CCDC18-AS1 shows elevated expression in breast cancer tissues and correlates with advanced disease stages 3. Notably, berberine treatment can upregulate CCDC18-AS1 expression in esophageal cancer, suggesting context-dependent regulatory roles 4. The lncRNA also shows potential as a therapeutic target, with its expression patterns predicting treatment response in adolescent major depressive disorder 5.