DDR1 is a class of collagen receptor, the upregulation of which has been widely associated with more aggressive behaviour in several malignant tumours including lung cancer, hepatocellular carcinoma, glioma and breast cancer.24,26–29 In the context of PCa; however, the clinical significance and the role of aberrant DDR1 expression remain unclear. The gene discussed is DDR1; the disease is hepatocellular carcinoma.