Prostate cancer patients have a much higher total PSA (which is the sum of free and bound PSA) with a lower free-PSA and higher bound-PSA fraction (Figure 4B); thus, measurement of the ratio of free/total PSA (which is the sum of free and bound PSA) can significantly increase the sensitivity and specificity of prostate cancer detection. The gene discussed is KLK3; the disease is prostate carcinoma.