RIGI and neoplasm: In addition to TLRs, other PRRs such as melanoma-differentiation antigen 5 (MDA-5) and retinoic acid-inducible gene I (RIG-I), largely involved in antiviral defense, have also been implicated in mediating tumor-cell apoptosis, DC priming and potentiation of anti-cancer cytotoxic T-cell activation (Wu et al., 2017).