PDGFRB and metastatic neoplasm: In a randomised placebo-controlled clinical trial of PDGFR inhibition with imatinib mesylate (Buchdunger et al, 2000) and docetaxel chemotherapy in men with castration-resistant prostate cancer and bone metastases, high-frequency expression of the target – phosphorylated PDGFR in metastatic tumour in bone – was confirmed, with the evidence of enhanced systemic inhibition of PDGFR phosphorylation measured in peripheral blood leukocytes and significant reductions in urine N-telopeptide, a bone lysis marker, in the docetaxel plus imatinib arm compared with docetaxel plus placebo arm.