The TMA synthesis inhibitor 3,3-dimethyl-1-butanol (DMB) has been found to prevent cardiac hypertrophy and fibrosis by modulating the transforming growth factor-β1 (TGF-β1)/Smad3 and p65 nuclear factor-κB (NF-κB) signaling pathways (35). The gene discussed is SMAD3; the disease is cardiac hypertrophy.