PDGFB and early-onset autosomal dominant Alzheimer disease: A very recent human study reported that elevated levels of circulating PDGF‐BB and loss of PDGFβ are associated with cerebrovascular damage specifically in individuals at genetic risk of Alzheimer's disease.[37] It is interesting to test if elevated PDGF‐BB at the conditions of Alzheimer's disease and small vessel disease also induces PDGFRβ shedding through MMP14 or other matrix metalloproteinases.