WD40 repeats are a common structural module in eukaryotic proteins, and proteins containing WD40 domains have a wide range of functions, including signal transduction, cell cycle regulation, RNA splicing, and transcription. One such protein, WDR92, also known as monad, contains two WD40 repeats is widely expressed in human tissues, especially testis. Overexpression of this protein or its binding partner RNA polymerase II-associated protein 3 (RPAP3) potentiated apoptosis and caspase-3 activation induced by TNF-α and cycloheximide, suggesting that WDR92, together with RPAP3, may function as a novel modulator of apoptosis.