In 2012, March-Villalba et al. reported that circulating plasma Telomerase Reverse Transcriptase (hTERT) mRNA is a potentially helpful diagnostic biomarker for prostate cancer, with a sensitivity of 85% and specificity of 90%; which compares favorably to serum PSA, which has sensitivity of 83% and specificity of 47% [55]. Here, KLK3 is linked to prostate cancer.