TLR7 and myocarditis: According to this hypothesis, the mRNA molecules released in endosomes or cytosol from the vaccine, acting as a mimic of viral mRNA, might be recognised as PAMPs by TLRs (e.g., TLR7 and TLR8) prior to the translation, therefore, stimulating the production of type I interferons and proinflammatory cytokines, which, as mentioned above, may have a role in the development of myocardial inflammation [124,126].