TLR7 and cancer: Among various cancer vaccine adjuvants, TLR7/8 agonists are of particular interest because of their strong activation of APCs (Napolitani et al., 2005), initiation of cross-priming, promotion of CD4+/8+ T and natural killer (NK) cell activation (Kastenmuller et al., 2011), ability to limit the immunosuppressive function of regulatory T (Treg) cells, and association with an inflammatory tumor microenvironment via induction of cytokines and chemokines (Peng et al., 2005; Vasilakos and Tomai, 2013).