The present invention relates to the significant functional role of several C. elegans genes and of their corresponding gene products in cell division and proliferation processes that could be identified by means of RNA-medicated interference (RNAi) and to the identification and isolation of functional orthologues of said genes including all biologically-active derivatives thereof. The invention further relates to the use of said gene products (including said orthologues) in the development or isolation of anti-proliferative agents, particularly their use in appropriate screening assays, and their use for diagnosis and treatment of proliferative diseases.