A linear regression analysis was performed between cfRNA and TC-associated mRNA values, and the resulting R-values, reported in Table 3, show a very high correlation between total CAIX mRNA in the supernatant and sediment in all tumors under study, while the correlation is lower in benign pathology (BPH) and even more so in the physiological conditions of healthy subjects. This evidence concerns the gene CA9 and benign prostatic hyperplasia.