MRPS6 (mitochondrial ribosomal protein S6) is a structural component of the mitochondrial small ribosomal subunit that plays essential roles in mitochondrial protein synthesis and cellular metabolism 1. As part of the mitoribosome, MRPS6 contributes to the translation of mitochondrial-encoded genes critical for oxidative phosphorylation 1. The protein demonstrates significant regulatory functions beyond ribosomal assembly, modulating glucose-stimulated insulin secretion in pancreatic β-cells through the mitochondrial unfolded protein response (UPRmt) pathway 2. MRPS6 maintains a negative feedback loop with UPRmt, where disruption leads to hyperactivation, increased ROS levels, and impaired insulin secretion 2. In cancer contexts, MRPS6 shows oncogenic properties, with overexpression promoting proliferation and mesenchymal markers in breast cancer cells 3. The protein also functions as an antiviral host restriction factor, inhibiting porcine deltacoronavirus infection through IFN-β pathway activation 4. MRPS6 expression is dysregulated in multiple diseases including Parkinson's disease, atopic dermatitis, and colorectal cancer, making it a potential therapeutic target 156. Clinical significance includes associations with myocardial infarction mortality and impaired glucose tolerance through genetic polymorphisms 72.