['Human platelet-derived growth factor BB (PDGF-BB) is thought to be involved in human malignancies. Its overexpression has been reported in some human tumors. However, its expression in colorectal cancer has not been studied. We thus investigated the clinicopathological and biological significance of PDGF-BB gene expression in human colorectal cancer.', 'Using real-time reverse transcription-PCR, we evaluated PDGF-BB expression status and correlated data with clinicopathological parameters in 60 patients with colorectal cancer. Additionally, we established a colorectal cancer cell line expressing PDGF-BB and investigated its effects on cell invasion and proliferation.', 'The incidence of vascular invasion was significantly greater in patients expressing PDGF-BB at a high level than in those at a low level (P < .05). Patients with high PDGF-BB expression had a significantly poorer survival rate than those with low PDGF-BB expression (P < .05). A multivariate analysis demonstrated that PDGF-BB expression was an independent prognostic factor. We demonstrated in vitro that cells transduced with PDGF-BB showed greater invasiveness (P < .05) and migration (P < .001) than did mock transduced cells. In a xenograft study, cells transduced with PDGF-BB had higher proliferation rates than mock transfected cells.'] Is pDGF-BB a novel prognostic factor in colorectal cancer?