PIN1 is overexpressed in several human cancers (Lee T. H. et al., 2011), including prostate cancer (Ayala et al., 2003; La Montagna et al., 2012), breast cancer (Wulf et al., 2001; Ryo et al., 2002), and oral squamous carcinomas (Miyashita et al., 2003). Here, PIN1 is linked to breast cancer.