TLR9 and neoplasm: A TLR7/8 agonist has the potential to activate a broader range of human APCs versus targeting TLR9 within the tumor microenvironment, since TLR7 and TLR9 are both expressed on plasmacytoid dendritic cells (pDCs) and B cells, whereas TLR8 is more widely expressed on monocytes and myeloid dendritic cells (mDCs) [20].