Disclosed are monoacylated Toll-like receptor 2 ligands which can be used in both the development of targeted agents for the imaging and treatment of pancreatic cancer as well as other cancers, and as an adjuvant for cancer immunotherapy. The monoacylated compounds disclosed herein have a higher binding affinity for TLR2 relative to a known potent diacylated agonists, but only −½ the bioactivity. Competition of the monoacylated compound with the diacylated compound for binding TLR2 was confirmed. Hence, the reported monoacylated compounds are inhibitors/antagonists of TLR2 activation.