Chen, D., Colditz, I.G., Glenn, G.M., Tsonis, C.G. Induction of systemic immune responses in sheep by topical application of cholera toxin to skin. (resumemycareer.com)
The possibility that they also stimulate a regional and even systemic immune response is exciting, as this potential effect may have utility in combination regimens; such regimens are an area of active research. (cancernetwork.com)
Animal experiments Cytosolic and secreted peptidoglycan - degrading enzymes in Drosophila respectively control local and systemic immune responses to microbiota — Bernard Charroux — Cell Host & Microbe (microbiomedigest.com)