PTK2 and glioblastoma: In addition, FAK inhibition by FAK inhibitor, PF573228 (PF57) or PF562271 (PF56), led to increased fluorescent intensity of MitoTracker labeling in both LN229 and U251MG GBM cells, indicating that FAK inhibition results in an increase in mitochondrial oxidative phosphorylation function (Figure 4A–D).