protein localized to the nucleus in proliferating cells that seems to possess a tumor suppressor activity. Directly interacts with the RNA helicase eIF4A and inhibits protein synthesis by interfering with the assembly of the cap-dependent translation initiation complex. Suppresses carbonic anhydrase type II protein expression in carcinoid cell lines. Since tumor cells require a high bicarbonate flux for their growth, carbonic anhydrase suppression results in growth inhibition. Expression of this gene is modulated by cytokines in natural killer and T cells. The gene product is thought to play a role in apoptosis but the specific role has not yet been determined. Two differentially spliced isoforms have been identified. Note: This description may include information from UniProtKB.