Several markers can be used to identify ER stress in tissue samples. These include: - CHOP (C/EBP homologous protein): A transcription factor that is upregulated during ER stress. - BiP/GRP78: An ER chaperone whose expression increases in response to ER stress. - XBP1: A transcription factor that plays a critical role in the UPR. - Phosphorylated eIF2α: Indicates activation of the PERK pathway, a key component of the UPR.
