Table 1 shows the distribution of numerical variables of the study. The differential expression of KLK5-8, KLK10, KLK11 and KLK13-15 was evaluated by the paired t-test on log-transformed values. As shown in Table 2, the means of kallikrein concentrations between cancer and normal samples were significantly different for all KLKs (P<0.001), with the exception of KLK5 (P=0.92) and KLK14 (P=0.87). This evidence concerns the gene KLK13 and cancer.