PDGFRB and early-onset autosomal dominant Alzheimer disease: It has been reported that elevated levels of soluble PDGFRβ (sPDGFRβ) in cerebrospinal fluid (CSF) are an early biomarker of human Alzheimer's disease.[39] Therefore, detecting soluble PDGFRβ in blood or urine could has a potential as biomarker for the diagnosis of CKD in the future.