SRC and glioblastoma: In support of this, activating phosphorylation of SRC in Trp53/Pten−/− cells increases ~3-fold with development of ispinesib resistance (Figure 3B), and treatment of four ispinesib-naive human GBM cell lines with 50 nM ispinesib enhances phosphorylated SRC 3- to 4-fold over vehicle by 24 h of treatment (Figure 3C).