MRPS18C encodes a mitochondrial ribosomal protein component of the small ribosomal subunit, essential for mitochondrial translation and energy metabolism 1. As a structural constituent of the mitochondrial ribosome, MRPS18C participates in mitochondrial translational processes and localizes primarily to the cytoplasm 2. Loss of MRPS18C function impairs ATP production and mitochondrial morphology; MRPS18C-null embryos fail to initiate gastrulation by embryonic day 7.5, revealing its critical developmental role 1. Clinically, MRPS18C shows significant disease relevance across multiple pathologies. In gestational diabetes mellitus, MRPS18C expression is substantially downregulated and identified as a hub gene regulated by transcription factors YY1 and ARID3A 2. In breast cancer, elevated MRPS18C expression associates with poor prognosis 3, and genetic variants affecting MRPS18C expression (rs11099601 on chromosome 4) represent a novel breast cancer susceptibility locus 4. Additionally, MRPS18C emerges as a hub gene in generalized aggressive periodontitis 5. Therapeutically, MRPS18C overexpression suppresses biochemical defects caused by mtDNA mutations, suggesting potential as a modifier gene for mitochondrial diseases 6. These findings establish MRPS18C as a critical mitochondrial component with broad implications for developmental biology, metabolic disorders, and cancer pathogenesis.