Examination of IGFBP3 expression in vitro, revealed that all of the prostate cancer cell lines expressed IGFBP3, including LNCaP cells whose methylation pattern was representative of the majority of prostate tumours analysed (heavily methylated at IGFBP3-A, remarkably fewer CpGs methylated at IGFBP3-B and unmethylated at IGFBP3-C). This evidence concerns the gene IGFBP3 and Familial prostate cancer.