Moreover, levels of lactotransferrin in saliva have been negatively associated with early diagnosis of Alzheimer's disease [39, 40], and a recent study showed that alpha-amylase was found in epithelial cells and appears to induce the proliferation and differentiation of these cells, particularly in the small intestine, maintaining a healthy intestinal environment [41]. The gene discussed is LTF; the disease is early-onset autosomal dominant Alzheimer disease.