DDIT3 and brain ischemia: We found the following: (a) T817MA attenuates neuronal injury and oxidative stress following OGD in HT22 cells, (b) T817MA inhibits intracellular ER Ca2+ release and CHOP expression, (c) T817MA exerts protective effects through the HSP70–HSP90 pathway following OGD, (d) T817MA reduces brain edema and preserves neurological function following brain ischemia, and (e) T817MA regulates ER stress and the HSP70–HSP90 pathway in vivo.