Bone Research Jul 12 2025 Estrogen plays an important role in keeping bones healthy. Now, researchers investigated how membrane-initiated estrogen receptor alpha (mERα) signaling in specific cell types of female mice affects bone health. They found that mERα activity in bone-forming cells (osteoblasts) is crucial for maintaining strong cortical bone, while its role in hematopoietic cells is minimal. These findings provide insights into how estrogen protects bone and could help develop safer