DDR1 and neoplasm: Upon orthotopic implantation of MDA-PATC 148CTL, MDA-PATC 148KD#32, and MDA-PATC 148KD#32-exDDR1 cells, we found that DDR1 knockdown in the cancer cells had no effect on primary tumor growth but resulted in a significant reduction in the incidence of liver metastasis (WT, 58.33%; KD#32, 12.5%; P value = 0.0272 in Fisher’s exact test) (Figure 1, D–F).