Cenexin1 is an isoform of ODF2, that unlike ODF2 is present in several somatic cell types. Cenexin1 acts as a general scaffold protein that is specifically localised to the distal/subdistal appendages of mother centrioles. Cenexin1 is required for proper localization of Plk1 to the centrosomes. This centrosomal localization of Plk1 is required for proper microtubule function. Cenexin1 recruits Plk1 via a C-terminal extension of cenexin1 that is not present in ODF2. Cenexin1 is required for proper mitotic progression; depletion of Cenexin1 ultimately leads to chromosome missegregation and apoptosis. The ODF2 (outer dense fiber 2) gene encodes both ODF2 and Cenexin1, which have very different functions. ODF2 is a major component of sperm tail outer dense fibers (ODFs). ODFs are filamentous structures located on the outside of the axoneme in the midpiece and principal piece of the mammalian sperm tail. They may help to maintain the passive elastic structures and elastic recoil of the sperm tail, and may also modulate sperm motility.