The Red blood cell distribution width-to-albumin ratio (RAR) has emerged as a significant composite biomarker, combining RDW and serum albumin to better reflect systemic inflammation, oxidative stress, and nutritional status. Recent studies indicate that higher RAR levels are independently associated with increased risk in cardiovascular health, such as atrial fibrillation and mortality, as well as potential applications in cancer risk stratification. For more detailed, peer-reviewed research on this topic, visit PMC .