The main ones include renal resistive index by US Doppler and biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C. Despite promising previous results [23, 24], renal resistive index was recently shown to be a poor predictor of persistent AKI with AUC close to 0.58 in a large multicenter study [25]. The gene discussed is CST3; the disease is acute kidney injury.