Using this modified LFIA with two combinations of biotinylated primary antibodies and nano-gold conjugated antibodies, we were able to establish standard calibration curves from huMETCAM/MUC18 recombinant proteins and used these curves to determine the serum METCAM/MUC18 concentrations in normal individuals, BPH patients, patients with PIN, prostate cancer patients with various Gleason scores, and treated prostate cancer patients. The gene discussed is MCAM; the disease is Familial prostate cancer.