To clarify the meaning and clinical value of bone formation markers in bone metastasis from prostate cancer, we investigated the bone formation markers carboxy-terminal propeptide of type I procollagen (PICP), bone-specific alkaline phosphatase (BA1-p) and osteocalcin, so-called bone gla protein (BGP) in 43 prostate cancer patients with and 46 patients without overt bone metastasis. The gene discussed is COL1A2; the disease is prostate cancer.