[The PSA gene: value in detection of circulating prostate cancer cells]

There has been a renewed interest in detection of circulating cancer cells due to the simplicity, specificity and sensitivity of a molecular biology technique: RT-PCR. This detection is based on the concept of specificity of an RNA sequence expressed by a cancer cell. PSA appears to be the ideal marker for circulating prostate cancer cells due to its specificity. The authors review the genes of the kallikrein family and discuss the advantages and difficulties involved in the use of PSA messenger RNA as a marker for circulating prostate cancer cells.