Previous researches have rarely been done to investigate the relationship between Pin1 and papillary thyroid carcinomas (PTCs); Masahiro et al. [21] confirmed Pin1 mRNA expression in PTC by RT-PCR in their investigation, and they pointed out that Pin1 immunoreactivity was significantly higher in PTC than in follicular adenomas (FAs), the same with Andrzej et al. study [22]. Here, PIN1 is linked to follicular thyroid adenoma.