DDIT3 and non-small cell lung carcinoma: To investigate whether PB01 modulates ER stress and DNA damage pathways in NSCLC cells, we measured the levels of ER stress proteins, such as p-PERK, PERK, p-eIF2α, eIF2α, ATF4, p-IRE1ɑ, IRE1ɑ, p-JNK, JNK, cleaved caspase-3, CHOP, and DNA damage protein GADD45ɑ using Western blot analysis in thapsigargin (TG)-treated NSCLC cells.