One study in patients with Alzheimer’s disease explicitly mentioned an absence of such correlations (Motta et al. 2007), but in that study, peripheral blood levels of TGF-β1 were measured in serum and were thus most likely largely attributable to TGF-β1 released from degranulated platelets (Grainger et al. 2000; Iłzecka et al. 2002). Here, TGFB1 is linked to early-onset autosomal dominant Alzheimer disease.