MRPS18A is a mitochondrial ribosomal protein component of the small ribosomal subunit that functions as a structural constituent of the mitochondrial ribosome involved in translation 1. As a mitochondrial protein, MRPS18A plays a role in mitochondrial energy metabolism, a hallmark process altered during cellular transformation 2. Mechanism: MRPS18A expression is regulated post-transcriptionally through a competing endogenous RNA mechanism, where the long noncoding RNA TRIM52-AS1 sponges miR-514a-5p, thereby preventing miRNA-mediated suppression of MRPS18A 1. Disease Relevance: MRPS18A is upregulated in hepatocellular carcinoma (HCC), where increased expression promotes cancer cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition; MRPS18A upregulation can rescue the anti-tumor effects of TRIM52-AS1 inhibition 1. Similarly, MRPS18A expression is elevated in breast cancer compared to normal breast tissue 2. Additionally, MRPS18A shows altered expression in Down syndrome neuronal differentiation, suggesting involvement in neurodevelopmental processes 3. Clinical Significance: A novel MRPS18A-PDC-AS1 gene fusion was identified as a potential diagnostic marker for differential diagnosis of uterine sarcomas, specifically distinguishing uterine leiomyosarcomas from endometrial stromal sarcomas 4. The TRIM52-AS1/miR-514a-5p/MRPS18A axis represents a novel therapeutic target for HCC treatment 1.