RPL12 (ribosomal protein L12) is a structural component of the large ribosomal subunit that binds directly to 26S ribosomal RNA and facilitates protein synthesis 1. Beyond its canonical ribosomal function, RPL12 has emerged as a conserved ribophagy receptor essential for selective ribosome turnover and cellular homeostasis 2. Atg1-mediated phosphorylation of RPL12 enhances its binding to Atg11, triggering ribophagy during starvation 2. RPL12 deficiency impairs stress responses, accelerating cell death during starvation and pathogen infection, while reducing lifespan and promoting motor impairments associated with aging in model organisms 2. Clinically, RPL12 has disease relevance in multiple conditions. In Alzheimer's disease, RPL12 expression is significantly upregulated in brain capillaries alongside enhanced protein processing machinery 3. Mendelian randomization analysis identified RPL12 as a risk factor causally associated with postmenopausal osteoporosis 4. In cystic fibrosis, RPL12 depletion slows translation velocity, restoring folding and function of the F508del-CFTR mutant protein 5. Additionally, RPL12 serves as a candidate biomarker in immune thrombocytopenia for distinguishing rituximab responders from non-responders 6. Post-translational methylation of RPL12 by Set11 occurs during ribosomal assembly 7.