SOX2 and pachyonychia congenita: In the present cohort of 206 prostatectomized PC patients, the mean level of SOX2 mRNA was found to be significantly (p < 0.05) downregulated in the neoplastic epithelium from both low- and high- Gleason grade PC foci (≤3 and >3), by 20.78 and 7.87 times, respectively (with no substantial differences between them), compared to the normal counterpart (whose expression levels were similar to those in the normal epithelium of the controls) (Figure 1A).