7-Allyl-7,8-dihydro-8-oxoguanosine (Loxoribine) is a small-molecule immunostimulant. Loxoribine is a toll-like receptor 7 (TLR7) agonist; induces immune cell activation and increases cytokine production. Loxoribine displays antitumor and antiviral activity in various animal models.