Rhophilin, a small GTPase Rho-binding protein, is abundantly expressed in the mouse testis and localized in the principal piece of the sperm tail.
Nakamura K, Fujita A, Murata T, Watanabe G, Mori C, Fujita J, Watanabe N, Ishizaki T, Yoshida O, Narumiya S. FEBS Lett. 1999 Feb 19; 445(1):9-13.