RIGI and central nervous system cancer: The LPA differs from the commonly used LNPs (Figure 1) that are size-limited to permit endocytosis; by contrast, the LPA-based mRNA vaccine does not rely on TLR for engagement, enabling the delivery of multiple mRNA payloads to the same cancer cell, as shown in a canine model of glioma using the LPAs to elicit a potent RIG-I (retinoic acid-inducible gene I protein)-mediated stimulation of the immune system (15).