Biomarkers are biological indicators used to measure the effects of treatment or the progression of a disease. In the context of HIV, biomarkers can help in early detection of drug-induced toxicity, allowing for timely interventions. Commonly used biomarkers include liver enzymes (such as ALT and AST), kidney function markers (such as creatinine), and markers for bone density (such as DEXA scans). Monitoring these biomarkers can help in adjusting treatment plans to minimize adverse effects.