TACC gene is associated with FGFR4 in vertebrate genomes. To date, only three active TACC genes have been cloned in humans [1-3], one in each of mouse [7], Xenopus laevis [8], D. melanogaster [4], and C. elegans [5,6]. Although two additional new candidate TACC family members, Oryctolagus cuniculus TACC4 [9] and human RHAMM [10] have been proposed, their true identity and placement in the evolution of the TACC family is under debate. Thus, the identification and functional charac