RPS3A (ribosomal protein S3A) is a component of the small ribosomal subunit that performs both canonical and non-canonical cellular functions 1. As a ribosomal protein, RPS3A participates in protein synthesis and ribosome biogenesis, with significant upregulation observed in brain capillaries of Alzheimer's disease patients 2. Beyond its ribosomal role, RPS3A exhibits diverse regulatory functions including transcriptional control and metabolic regulation. In adipose tissue, RPS3A migrates to mitochondria to maintain brown adipocyte function and regulate UCP-1 expression, with decreased expression associated with coronary artery disease progression 3. RPS3A also serves as a transcription regulator, promoting glioma progression by upregulating CSF1 through interaction with transcription factor E4F1, thereby recruiting tumor-associated macrophages and promoting their M2 polarization 4. Additionally, RPS3A interacts with BTN3A3 to regulate cellular ROS levels and MAPK signaling in renal cell carcinoma 5. The protein participates in viral replication processes, influencing SARS-CoV-2 programmed ribosomal frameshifting 6. These findings establish RPS3A as a multifunctional protein with roles in translation, metabolism, immune regulation, and disease pathogenesis.