PDGFRA and schwannoma: Schwannomas exhibited averaged 6.6 times higher PDGFRα phosphorylation, 5.4 times higher PDGFRβ phosphorylation, 30 times higher SRC phosphorylation, 5.6 times higher MEK phosphorylation and 7.4 times higher STAT3 phosphorylation compared with control primary HSC (Figure 7 A-D).