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. This condition is linked to several diseases, including diabetes, neurodegenerative disorders, and cancer. Understanding ER stress is crucial for developing potential therapies for these health issues.