In this study, we found that the protein levels of TLR4, MyD88, NLRP3, caspase‐1, and IL‐1β in atrial tissues were markedly increased in the SHR‐AF group compared to those in the SHR group, whereas downregulation of FMOD decreased the protein levels in atrial tissues of the SHR‐AF group. This evidence concerns the gene TLR4 and atrial fibrillation.