Statistical analysis was performed using 21.0 SPSS Statistical Package (SPSS, 2003). Fisher’s exact test and independent-samples t-test were performed to correlate NIS and SLC5A5 mRNA expression with clinicopathological and molecular features. When parametric tests were not applicable, we used alternative tests, specifically Mann–Whitney (independent samples). Wilcoxon (related samples) was used to compare SLC5A5 expression between tumor samples and their adjacent normal counterparts. Kruskal–Wallis test was used to correlate SLC5A5 expression (retrieved from TCGA and database) with clinicopathological and molecular features. Values of P ˂ 0.05 were considered statistically significant.