TLR8 and cancer: Resiquimod is an imidazoquinoline with antiviral and antitumor activity in preclinical animal models33,34 and clinical activity as an adjuvant to vaccines35 and cancer immunotherapy36 and is currently licensed by the European Medicines Agency for the treatment of cutaneous T cell lymphomas.37,38 Resiquimod can activate both human intracellular receptors for ssRNA, TLR8 and TLR7.39 Since TLR7 is not expressed in human macrophages40 (Figure S3), resiquimod activity is abolished in Mtb-infected human TLR8−/− macrophages (Figure S2) but preserved in TLR7−/− cells (Figure S3).