LCN2 and peripheral arterial disease: Correlation analyses between the above markers and PAD severity showed a significant, though weak, negative correlation between NGAL and the following parameters: 6-min pain-free walking distance (6PFWD) (ρ −0.298; p = 0.025), pain-free walking distance (PFWD) (ρ −0.256; p = 0.046), and maximal walking distance (MWD) (ρ −0.305; p = 0.017).