Abstract: The endoplasmic reticulum (ER) is a place where secreted proteins and membrane proteins are synthesized and folded. The homeostatic environment of the endoplasmic reticulum is necessary to keep ER protein synthesis proceed smoothly. When unfolded proteins and misfolded proteins aggregate in the ER abnormally, it often leads to protein synthesis disorder and triggers endoplasmic reticulum stress (ERS). The endoplasmic reticulum can maintain the endoplasmic reticulum homeostasis and restore cellular function by inducing an unfolded protein response (UPR). However, as the ERS increasingly intensify, the continuous UPR reaction will trigger programmed cell death. There is close relationship between the tumorigenesis of lung cancer and ERS in cells. This article will introduce ERS, UPR and related pathways, and summarize their main causes and their roles in lung cancer, aiming to providing new ideas and potential therapeutic targets for basic research and clinical treatment of lung cancer. 

Key words: endoplasmic reticulum stress, unfolded protein response, pathway inhibitor, lung cancer