CA9 and neoplasm: In contrast to the NAT tumor group, the statistical analysis of the UT biopsy and the UT surgical specimen did not result in statistical difference regarding CAIX expression (mean 15.0 ± 21.3 SD vs. 20.0 ± 23.02, Wilcoxon matched rank test p < 0.073) but the correlation between the biopsy and surgical samples could be well established (Spearman correlation test p < 0.0001, rho: 0.8077) (Figure 5A,B).