The SLC5A5 expression was around 200 times higher in normal tissue than in tumor tissue in both genders, but no differences in tumor and in adjacent tissue between genders were found (Fig. 2A and B). SLC5A5 expression was significantly higher in smaller tumors ≤2 cm (median = 5.85) compared to those with >2 cm (median = 2.51) (P = 0.028; Fig. 2C). There was no statistical difference in SLC5A5 expression in primary tumors with (median = 3.0) or without (median = 5.4) lymph node metastases at the time of diagnosis (P = 0.253) (Fig. 2D). Figure 2SLC5A5 expression in primary PTCs (RPKM), data retrieved from TCGA database. Comparative analysis of SLC5A5 expression. (A) Between genders in tumor (TT) and normal tissue (NT); (B) between genders only in tumor tissue (TT); (C) in tumors with ≤2 cm and >2 cm; (D) in cases with or without lymph node metastases at the time of diagnosis; (E) in cases without, with minimal (T3) and with moderate/advanced extrathyroidal extension (T4a+b); (F) in cases with and without recurrence and (G) between cases with different genetic backgrounds (WT, RAS mutation, TERTp mutation, BRAF mutation, BRAF + TERTp mutation). The boxes represent the interquartile range; the whiskers are the 5% and 95% quartiles; the small open boxes are the mean values and the lines are the median values. Significant values for the Kruskal–Wallis test are indicated.