Forkhead box O3 (FOXO3) is a transcription factor that regulates critical processes like cell survival, cell cycle control, apoptosis, metabolism, and stress responses. The FOXO3 luciferase reporter vector is designed to study the transcriptional activity of FOXO3. The vector contains a FOXO3 DNA consensus binding site and TA minimal promoter upstream of a firefly luciferase reporter gene, which can specifically report FOXO3 activity while maintaining a low basal level of transcription.