DDIT3 and gastric cancer: GC, gastric cancer; PTE, pterostilbene; PTE-L, low-dose PTE; C, control; DOX, doxorubicin; LAP, lapatinib; IC, inhibitory concentration; ER, endoplasmic reticulum; GADD45, growth arrest and DNA damage inducible 45; CHOP, CCAAT/enhancer-binding protein homologous protein; PARP, poly ADP-ribose polymerase; BCL2, B cell lymphoma 2; BAX, BCL-2-associated X protein; C, control; FER, ferrostatine-1; DFO, deferoxamine; NAC, N-acetyl-L-cysteine; ZVAD, Z-VAD-FMK; 4PBA, 4-phenylbutyric acid; siC, control small interfering RNA; siCHOP, small interfering RNA for CHOP.