Osteoporosis (OP) is a common systemic metabolic disease in the elderly. It is characterized by bone pain, decreased bone strength, increased bone fragility, and degeneration of bone tissue. Osteoporosis is marked by low bone mineral density (BMD), which is associated with endoplasmic reticulum stress. The development of the pancreas and skeletal muscle system after birth is required to pass the PERK-eIf2α signaling pathway. PERK-eIF2α pathway can be activated by endoplasmic reticulum stress. ATF4 is a downstream target molecule of the PERK pathway, and ATF4 can stimulate cBFA1 to induce the expression of osteocalcin (OCN) in osteoblasts. These results indicating that endoplasmic reticulum stress is closely related to osteoporosis and bone development.This is a page.