APP and neuroblastoma: At similar concentrations, Yang et al. [53] showed that treatment with 10 μg/mL SiO2-NPs sized 15 nm for 24 h, induces altered expression of amyloid precursor protein (APP) and neprilysin, enhances phosphorylation of tau, and activates the glycogen synthase kinase (GSK)-3β in human SK-N-SH and rodent neuroblastoma cells.