Consistent with previous studies showing that knockdown of BIP expression could inhibit GBM cell proliferation and increase TMZ sensitivity [34], our data further supported that inhibition of eIF2α phosphorylation or silencing ATF4 expression effectively inhibited cell viability, cell migration and invasion, and promoted cell apoptosis in the TMZ-resistant GBM cells. The gene discussed is ATF4; the disease is glioblastoma.