TLR2 and cancer: First, a phase I clinical trial using the Bacillus Calmette-Guérin (a strong immune adjuvant for cancer immunotherapy and a mixed TLR2/TLR4 agonist) [102] on 18 patients with different cancers refractory to standard therapies (7 melanoma, 5 colorectal, 4 hepatobiliary, 1 ovarian, and 1 lung cancer) showed that the compound was well tolerated and induced an appropriate immune response.