KLK3 and Familial prostate cancer: For example, Kloss-Brandstätter et al. observed that patients with prostate cancer and a somatic mutation in mitochondrial tRNAs have significantly higher prostate specific antigen (PSA) values at diagnosis than patients without a somatic tRNA mutation (14.25 ± 5.44 versus 7.15 ± 4.32 ng/mL; p = 0.004).