In another example, myocardial infarction was found to be attenuated in TLR3-deficient mice as a result of the activation of the TLR3-TRIF pathway by extracellular RNA (exRNA) released from damaged tissue, although the authors did not define the source and identity of the RNA (Chen et al., 2014). Here, TLR3 is linked to myocardial infarction.