It has been over 70 years since the discovery of cellular immunity. Further investigation revealed that the even if immune cells are lysed and the molecular size limited to 8kDa, such injections retain some of the immunity-transferring properties. The term “transfer factor” (TF) was coined to denote the undiscovered substance responsibly for this phenomenon. Yet despite early interest, TF was all but abandoned in the 1990’s; in part due to unsubstantiated and fraudulent claims as well as the discovery of HIV, which suspended consideration of deriving therapy from blood. However, while TF was shelved as poorly elucidated, no clear explanation was provided for the observation of a small molecule harboring antigen-specific properties and therapeutic potential. Reopening this chapter, we discovered transfer factor is produced by memory T-cells and acts directly upon dendritic cells in an antigen-specific manner; ultimately activating mucosal immunity via Tc17 pathways. Antigen-targeted TF enhanced inflammatory response in models against Candida as well as S. aureus. Mass spec data suggests TF is hybrid compound, predicted to containing elements of peptides and nitrogenous bases. Finally, we provide ex vivo human data to demonstrate the therapeutic potential of TF and even attempt to address some of the past’s more fanciful claim. This report represents transfer factors’ resurrection and provides a modern scientific investigation into this once forgotten area of immunology.