Midkine is involved in numerous processes that promote cell growth, and may contribute to the pathogenesis of inflammatory diseases.1,4 Proteomic analyses have found that Midkine is highly enriched in amyloid-beta plaques, indicating its potential as a biomarker and/or therapeutic target for Alzheimer’s Disease (AD).5–7 Mechanistic studies would be greatly facilitated by the availability of high-quality antibodies for Midkine. Here, MDK is linked to Alzheimer disease.