PTK2 and glioma: In a more recent analysis of endometrial cancer cells, the expression of L1CAM promoted the expression of focal adhesion kinase (FAK) and activation of the FAK–GRB2 (growth factor receptor-bound protein 2)–SOS (Son of Sevenless)–RAS (Rat Sarcoma) pathway [37]; FAK is encoded by the protein tyrosine kinase 2 gene (PTK2), which in glioma cells interacts with L1CAM to allow FAK production [37].