Endoplasmic Reticulum (ER) Stress occurs when the endoplasmic reticulum, a cell organelle responsible for protein folding and processing, becomes overwhelmed. This can happen due to various factors, such as an accumulation of misfolded proteins, changes in calcium levels, or environmental stressors. When the ER is stressed, it triggers a protective response to restore normal function. If the stress persists, it can lead to cell dysfunction or death. Chronic ER stress is linked to several diseases, including diabetes, neurodegenerative disorders, and cancer. Understanding this process is crucial for developing potential therapies to mitigate its harmful effects.