Table 1. Guanine analogs activate TLR7 but not TLR8.

Guanine derivatives	Activation of TLR7	Activation of TLR8
Guanosine (G)	No	No
Deoxy-Guanosine (dG)	No	No
8-OH-dG	No	No
8-Aza-chlorophenyl-G	No	No
9-Phenyl-G	No	No
7-Deaza-9-benzyl-G	No	No
6-Chloro-7-deaza-G	No	No
6-Methoxy-7-deaza-G	No	No
7-Deaza-dG	Yes	No
7-Deaza-G	Yes	No
7-Thia-8-oxo-G (TOG)	Yes	No
8-Bromo-G	No	No
7-Methyl-G	No	No
7-Allyl-8-oxo-G (Loxoribine)	Yes	No
Imiquimod	Yes	No
R-848	Yes	Yes