PTK2B and central nervous system cancer: We determined that soluble factors released from microglia and contained in MCM up-regulate the expression of Epidermal Growth Factor Receptor (EGFR), Phospholipase C gamma 1 (PLCγ1) proteins, and most markedly, it significantly increased the phosphorylation levels of Pyk2 at Tyr 579/580 (Table 1), thereby stimulating the Pyk2 signaling pathway in glioma cells.