Notes: An ENPP1 inhibitor (apparent Ki = 0.11 µM); selective for ENPP1 over ENPP2 and ALP (apparent Kis = 5.5 and >100 µM, respectively) and a panel of 468 kinases at 1 µM; inhibits the extracellular degradation of cGAMP in ENPP1-overexpressing and cGAS-expressing 293T cells (IC50 = 0.340 µM); increases mRNA expression of the gene encoding IFN-β in CD14+ primary human PBMCs incubated with conditioned medium from ENPP1-overexpressing and cGAS-expressing 293T cells cultured with STF-1084; increases the percentage of tumor-associated CD11c+ cells among APCs in a 4T1 murine mammary cancer model in combination with ionizing radiation