<p>Citron Rho-interacting kinase (CRIK) is a dual specificity protein kinase, which catalyses the autophosphorylation and phosphorylation of exogenous substrates on both serine/threonine and tyrosine residues [<cite idref="PUB00035070"/>]. It plays an important role in the regulation of cytokinesis and the development of the central nervous system. It is required for KIF14 localization to the central spindle and mid-body. It is also a putative RHO/RAC effector that binds to the GTP-bound forms of RHO and RAC1. </p><p>This protein occurs in at least two different isoforms: CRIK (about 240kDa), in which the kinase domain is followed by the sequence of Citron (a Rho/Rac binding protein); and CRIK-short kinase (CRIK-SK, about 54kDa), which consists mostly of the kinase domain. CRIK may fulfil more specialised functions in specific cell types [<cite idref="PUB00035070"/>]. </p>