MRPL20 (mitochondrial ribosomal protein L20) is a structural component of the mitochondrial large ribosomal subunit involved in mitochondrial translation [GO annotations]. While its canonical function relates to ribosomal structure and RNA binding within mitochondria, recent evidence suggests broader disease associations. An antisense lncRNA transcript (MRPL20-AS1) shows clinical relevance to obstructive sleep apnea syndrome (OSAS), where expression is inversely correlated with disease severity as measured by apnea-hypopnea index 1. In cancer biology, MRPL20 emerged as a hub gene associated with cell migration in breast cancer progression; low MRPL20 expression correlated with poor prognosis in transcriptomic analyses 2. Additionally, differential DNA methylation near MRPL20 was identified in association with nasal microbiome composition in adolescents, suggesting links between microbial dysbiosis and epigenetic regulation of mitochondrial function 3. MRPL20 was also incorporated into a 16-gene risk predictive model for breast cancer prognosis, showing significant discriminative ability between recurrence and relapse-free patients 4. These findings indicate MRPL20 may have clinical significance beyond its structural ribosomal role, with potential implications in sleep-disordered breathing, cancer progression, and host-microbiome interactions.