Cells respond to the accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) by up-regulating ER-resident enzymes at the transcription level. This is referred to the unfolded protein response (UPR).

• 未折叠或错误折叠的蛋白质在内质网(endoplasmic reticulum,ER)中聚集促使细胞做出适应性反应,包括上调位于内质网的各种酶和分子伴侣,这被称为未折叠蛋白反应(unfolded protein response,UPR)。