Objective: To investigate the expression and clinical signi ficance of S100A4 gene in transitional cell carcinoma of bladder(TCCB). Methods: The expression of S100A4 gene in 38cases of TCCB and corres ponding non-cancerous tissues was examined by RT-PCR. Results: The posi tive rates of S100A4 gene in TCCB and non-cancerous tissues were 60.5%(23/38)and 0%(0/38)

respectively. The expression level of S100A4 gene in TCCB was significantly higher than that in normal bladder urothelial tissues(P<0.005).The expression rate ofS100A4 gene in TCCBwas posi tivelycorre-lated with tumor grade

clinical stagand lymph node metas tasis(P<0.05).Conclusion: S100A4 gene is correlated to TCCB different iation and may become a new marker of TCCB. Differential expression of S100A4 gene is correlated to invasion and metastasis of TCCB.S100A4 may be one of the markers for assessment of the progress of the cancer and clinical treatment instruction for TCCB.