For example, proteomic techniques have revealed the presence of AD-related peptides within aqueous humor samples [183], while tear fluid has proven to be clinically relevant through the discovery of a combination of four tear proteins, namely lipocalin-1, dermicidin, lysozyme C and lactritin, with a sensitivity of 81% and a specificity of 77% for AD [184,185]. The gene discussed is LCN1; the disease is Alzheimer disease.