With this funding opportunity announcement, the National Institute of Arthritis and Musculoskeletal and Skin Diseases encourages applications for support of innovative, exploratory/developmental projects aimed at studying the spectrum of activities of skeletal muscle in health and disease that are beyond its role in contraction and locomotion. These activities include endocrine and paracrine functions of skeletal muscle, resting muscle thermogenesis, sensing of biomechanical stimuli, storing amino acids, regulating systemic metabolism, etc. Advancing understanding of these important functions of muscle may lead to novel strategies for the prevention or treatment of common conditions such as cachexia, obesity, diabetes and sarcopenia.