Endoplasmic reticulum (ER) stress is characterized by the accumulation of misfolded and unfolded
proteins within the ER lumen. Such a cellular condition is implicated in the pathogenesis of
various diseases, including type 2 diabetes, Alzheimer's, Parkinson's, amyotrophic lateral sclerosis
(ALS), liver fibrosis, and hepatocellular carcinoma (HCC).
Despite the critical role of ER stress in cell survival and function, a significant challenge in ER stress
research has been the lack of a reliable surface marker to isolate live ER-stressed cells using conventional
cell sorters. This limitation is also a hurdle in biopharmaceutical manufacturing, where selecting
healthy, high-productivity cell lines is crucial, but difficult to achieve without such markers.
