The variability of KIM-1 levels can be attributed to multiple factors, including interindividual genetic differences—such as the expression of distinct splice variants (KIM-1a and KIM-1b) with potentially divergent biological behaviour— the influence of comorbid conditions like diabetes, hypertension, chronic kidney disease, and baseline renal function, which may confound interpretation in non-oncologic settings. Here, HAVCR1 is linked to chronic kidney disease.