WRG-28 is a selective, extracellularly acting DDR2 allosteric inhibitor, with an IC50 of 230 nM. WRG-28 inhibits tumor invasion, migration and tumor-supporting effects of cancer-associated fibroblasts (CAFs). WRG-28 inhibits metastatic breast tumor cell colonization in the lungs. WRG-28 also shows good activity of relieving rheumatoid arthritis in CAIA model of mice.