SMAD1 (Mothers Against Decapentaplegic Homolog 1, MAD Homolog 1, Mothers Against DPP Homolog 1, JV4-1, Mad-related Protein 1, SMAD Family Member 1, SMAD 1, hSMAD1, Transforming Growth Factor-beta-signaling Protein 1, BSP-1, BSP1, MADH1, MADR1) Antibody