PDCD5 (Programmed cell death 5) encodes a protein expressed in tumor cells during apoptosis independent of the apoptosis-inducing stimuli. Prior to apoptosis induction, this gene product is distributed in both the nucleus and cytoplasm. The conformation of PDCD5 protein is a stable helical core consisting of a triple-helix bundle and two dissociated terminal regions. This is an important novel protein that regulates both apoptotic and non-apoptotic programmed cell death.