Since Gfi1 loss of expression is a common event in different tumor types and its biological role in prostate has not been defined, we decided to characterize the DNA methylation status of Gfi1 promoter in the LNCaP, PC3, and DU145 prostate cancer cell lines by methylation-specific PCR (MSP) and bisulfite genomic sequencing of a region surrounding the transcriptional start site. The gene discussed is GFI1; the disease is Familial prostate cancer.