Two mutations were detected: an A----G transition causing a glutamine to arginine amino acid substitution at codon 61 of the Ha-ras gene in a primary prostatic duct adenocarcinoma and a G----T transversion causing a glycine to valine amino acid substitution at codon 12 of the Ha-ras gene in a prostate tumor cell line (TSU-PR1) derived from a lymph node metastasis.