TAIP2 was isolated as one of the homologous genes of TAIP3 (TGF-beta-up-regulated apoptosis-inducing-protein chromosome 3). The transcript of the mouse counterpart of TAIP2, designated mTaip2, was detected in several tissue specimens from embryos to adults, while mTaip2 was dominantly expressed in the embryonic brain. The overexpression of the full-length mTaip2 induced cell death in various cell lines. An analysis of mTaip2 deletion mutants revealed that the N-terminal half of mTaip2, but not the C-terminal half, had nuclear localization and cell death-inducing activities. The results indicate that mTaip2 is a novel cell death-related gene dominantly expressed in the embryonic brain, thus suggesting that mTaip2 may play a role in development of the brain.