DDR1-IN-6 is a potent and selective inhibitor of Discoidin Domain Receptor family member 1 (DDR1), exhibiting remarkable inhibitory activity at an IC50 of 9.72 nM. It effectively suppresses the auto-phosphorylation of DDR1b (Y513) with an IC50 value of 9.7 nM. Furthermore, DDR1-IN-6 displays strong anti-cancer activity.