FABP1 and acute kidney injury: In contrast, L‐FABP excretion reflects the tubular response due to ischemia and oxidative stress, and increases from the early stages of pathological events before structural damage of the glomerular, tubular, and both cells.33, 37 Other biomarkers, such as urinary albumin41 and N‐acetyl‐β‐d‐glucosaminidase (NAG),16 are used to diagnose early stages of AKI and CKD in cats.