Our research objective is to discover small molecules capable of regulating immune-related functionalities, targeting Toll-like Receptor (TLR) and Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 (ENPP1) based on ligand focused approach. I. TLR, as one of the Pattern Recognition Receptors (PRRs), possesses various subtypes. TLR agonists function as immune response enhancers and are currently being researched as vaccine adjuvants and potential therapeutics for cancer and infectious diseases. Moreover, TLR antagonists have the potential to serve as therapeutic agents by reducing overactive immune responses in autoimmune diseases and chronic inflammation. Both TLR agonists and antagonists are applied as immunomodulators in cancer immunotherapies. We focused on the subunits of Endosomal TLRs, specifically TLR3, TLR8, and TLR9, and synthesized dozens of compounds to identify those activating these subunits. II. ENPP1 inhibitors can activate the innate immune system, turning a cold tumor into a hot tumor. Therefore, the synthesis of compounds inhibiting ENPP1 is anticipated as a new strategy to overcome the limitations of immune checkpoint inhibitors using the adaptive immune system, driving active research in recent years. We synthesized various derivatives for each target with the ability to regulate immune-related functionalities and validated their activities in vitro.