Inhibition of PTK2 blunts R-dependent cell death. (A) SU-DHL-6 cells were treated with R and a PTK2 small-molecule inhibitor (PF-573228) or vehicle control (DMSO) for 24 hours, and cell death was assessed by Annexin V/propidium iodide staining and flow cytometry. Data were normalized to isotype control antibody. (B) Confirmation of pPTK2 Y397 reduction by the PTK2i was determined by western blotting (WB). DMSO, dimethylsulfoxide.