AIM: To investigate if CD44v6 could be used as a molecular marker of cancer progression and metastasis through the detection of CD44v6 gene expression in normal human peripheral blood.METHODS: RNA was extracted from the peripheral blood mononuclear cells of 50 healthy donors, the expression of CD44v6 was investigated using reverse transcriptasepolymerase chain reaction (RT-PCR).RESULTS: CD44v6 mRNA was detected in 58% of healthy volunteers under the proper controls.CONCLUSION: Our results suggest that the measurement of CD44v6 expression in peripheral blood by RT-PCR is not suitable for detection of circulating tumor cells.