Results We have performed an extensive database analysis to determine the genomic and cDNA sequences of the TACCs from phylogenetically diverse organisms. This analysis has determined the phylogenetic relationship of the TACC proteins to other coiled coil proteins, the resolution of the placement of the rabbit TACC4 as the orthologue of human TACC3, and RHAMM as a distinct family of coiled coil proteins. We have also extended the analysis of the TACCs to the interaction databases of C. elegans and D. melanogaster to identify potentially novel TACC interactions. The validity of this modeling was confirmed independently by the demonstration of direct binding of human TACC2 to the nuclear hormone receptor RXRβ.