One ROCK is not like another he mammalian rho kinases, ROCKI and ROCKII, control distinct cytoskeletal functions from distinct locations, report Yoneda et al. on page 443. ROCKI is required for formation of actin stress fibers and cell adhesion, whereas ROCKII is needed for phagocytosis. The ROCK proteins are major effectors of the Rho signaling pathway, controlling cell adhesion, motility, and...