Smad4 is required to inhibit osteoclastogenesis and maintain bone mass.

Morita M, Yoshida S, Iwasaki R, Yasui T, Sato Y, Kobayashi T, Watanabe R, Oike T, Miyamoto K, Takami M, Ozato K, Deng CX, Aburatani H, Tanaka S, Yoshimura A, Toyama Y, Matsumoto M, Nakamura M, Kawana H, Nakagawa T, Miyamoto T. Smad4 is required to inhibit osteoclastogenesis and maintain bone mass. Sci Rep. 2016 Oct 12;6:35221. doi: 10.1038/srep35221.