Inhibits translation initiation and cap-dependent translation. May excert its function by hindering the interaction between EIF4A and EIF4G. Inhibits the helicase activity of EIF4A. Binds RNA (By similarity). Does not seem to be involved in apoptosis. Interacts with EIF4A. Shuttles between the nucleus and cytoplasm. Predominantly nuclear under normal growth conditions. Expressed in a broad spectrum of hematopoietic organs, such as thymus and bursa. Lower levels of expression detected in the kidney. Up-regulated by viral v-myb. Belongs to the PDCD4 family.