MPPE1 and cancer: Whereas, the global distribution of TLRs and other innate immune receptors is largely known (32) and the use of TLR agonists in cancer immunotherapy has been in the spotlight for many years, the fact that TLR3 is particularly found in CD103+ cDC1 inside the tumor, sets it apart from the rest of TLRs and turns it into an attractive target for immunotherapy.