In a clinical study that enrolled 41 patients with mild cognitive impairment (MCI), 62 patients with Alzheimer's disease and 38 healthy elderly control subjects, it was found that MCI, which is a prodromal-inflammation stage of Alzheimer's disease, is correlated with elevated plasma LCN2 levels (Choi et al., 2011). Here, LCN2 is linked to Alzheimer disease.