Enpp-1-IN-1 is a potent and selective inhibitor of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), an enzyme involved in regulating extracellular nucleotide and nucleoside levels. Its primary application lies in cancer immunotherapy research, where it enhances the cGAS-STING pathway by preventing the breakdown of cyclic dinucleotides such as 2'3'-cGAMP. By inhibiting ENPP1, this compound promotes sustained activation of the STING pathway, leading to increased type I interferon production and improved antitumor immune responses. It is also being explored in combination with immune checkpoint inhibitors to overcome resistance in "cold" tumors, helping convert them into "hot" tumors that are more responsive to immunotherapy. Additionally, Enpp-1-IN-1 has shown potential in preclinical models for reducing tumor growth and metastasis, particularly in cancers with high ENPP1 expression such as breast, lung, and pancreatic cancers. Its role in modulating the tumor microenvironment makes it a valuable tool in developing novel anticancer therapies.