PDGFRB and neurodegenerative disease: Mutations in either PDGF-β or its receptor PDGF-R-β lead to primary familial brain calcification (PFBC), a neurodegenerative disease that involves accumulation of hydroxyapatite (HAp) calcium crystals within the basal ganglia and thalamus leading to parkinsonian-like symptoms (Tadic et al., 2015).