A moderate correlation between blood NfL level and eGFR was observed in the HC (r =  − 0.446, 95% CI: − 0.652, − 0.178, p = 0.0019) and DM group (r =  − 0.473, 95% CI: − 0.578, − 0.355, p < 0.0001), indicating that approximately 20% of the variability in blood NfL levels can be explained by renal clearance (Fig. 2). The gene discussed is NEFL; the disease is diabetes mellitus.