PID1 and brain neoplasm: Our findings in medulloblastoma and glioma cells show for the first time that PID1 increases apoptosis induced by etoposide and cisplatin, that siRNA-mediated downregulation of PID1 suppresses cisplatin-mediated apoptosis, and that etoposide and cisplatin increase PID1 mRNA in an NFκB-dependent manner, suggesting that PID1 mediates part of the responsiveness of these brain tumor cell lines to chemotherapy (Fig. 6).