Updated FTP location. This project is “Medical proteome analysis of osteoporosis- and bone mass-related proteins using the Kibo Japanese Experiment Module of International Space Station (ISS)”. Applying proteomic technologies, this research aims to identify proteins involved in space flight-induced osteopenia as well as osteoporosis occurring on the ground by searching serum, bone and skeletal muscle (soleus, extensor digitorum longus) proteomes. The goal of this study is to get better understanding to protect the health of both astronauts and osteoporosis patients. Proteome analyses of skeletal muscles from 10 male C57BL/6J mouse (1-g gravity and 3-g gravity [n=5, respectively]) were carried out tryptic digestion followed by LC-MS/MS analysis (DDA). The obtained results were searched against UniProt DB by Mascot, and the identified peptides were filtered at 1% FDR threshold by searching against the randomized decoy DB.