D73-IN-14 is a potent, selective and orally active CD73 inhibitor with an IC 50 value of 0.17 nM. CD73-IN-14 increases the number of tumor-infiltrating CD8 + cells and shows anti-tumor activity. CD73-IN-14 is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.