SMADs are a family of transcription factors that mediate signals from growth factors and play a crucial role in various cellular processes, including embryonic development, cell proliferation, differentiation, apoptosis, immune regulation, and fibrosis. The SMAD luciferase reporter vector is designed to study the transcriptional activity of SMAD. The vector contains a SMAD DNA consensus binding site and TA minimal promoter upstream of a firefly luciferase reporter gene, which can specifically report SMAD activity while maintaining a low basal level of transcription.