SMAD3 and myocardial infarction: Our findings, which showed that the migration and proliferation of human CFs and the expression of collagen I, collagen III, smad2, smad3 and smad4 and the phosphorylation levels of smad2 and smad3 were higher in si‐smad7 groups than in the relevant control groups, indicated an essential role for smad7 in post‐MI cardiac healing.