TLR7 and COVID-19: In addition to COVID-19, multiple tumors' tumorigenesis has been reported to involve TLR7, and treating infectious diseases and cancer with immunotherapy has become a potent clinical strategy. For example, Resimod (R848), a TLR7 agonist, was effective in treating several cancers, including breast, pancreatic, and colorectal cancer [14], [15], and alum adjuvant and built-in TLR7a work together to enhance MUC1 glycopeptide-specific memory CD8+ T cell immunity [16].