Based on limited published evidence, PNMA3 is a neuronal protein with brain and testis-restricted expression 1. Database annotations indicate PNMA3 functions in protein binding and positive regulation of apoptotic process. PNMA3 is a retrotransposon-derived gene that generates alternative protein isoforms through -1 programmed ribosomal frameshifting, a mechanism conserved across mammals 2. By analogy to pro-apoptotic MOAP1, PNMA3 may interact with bcl-2 family members to regulate apoptosis 1.