TLR9 and melanoma: While resiquimod, a TLR7/8 agonist, showed an immunomodulatory effect on melanoma patients (NCT00960752), another TLR9 agonist, tilsotolimod, was tested in combination with standard immune checkpoint inhibitors (ICIs) in the treatment of advanced melanoma patients, showing beneficial effects as compared with ICIs alone (NCT03445533).