Gardiquimod is an experimental drug which acts selectively at both mouse and human forms of toll-like receptor 7 (TLR7). It functions as an immune response modifier. The core structure is 1H-imidazo[4,5-c]quinoline, as found in related drugs such as imiquimod and resiquimod. It is structurally very similar to resiquimod differing only by an oxygen for nitrogen switch.