Given the urgent need for early AKI prediction in pediatric sepsis, this study focuses on leveraging Red Blood Cell Distribution Width (RDW) along with key inflammatory and renal biomarkers—Procalcitonin (PCT), Interleukin-6 (IL-6), C-reactive Protein (CRP), and Cystatin C. RDW reflects erythrocyte variability and has been associated with systemic inflammation and oxidative stress, both of which play significant roles in sepsis and AKI. The gene discussed is CST3; the disease is acute kidney injury.