CPE and glioblastoma: Höring et al. (2012) reported that the expression of CPE was reduced in glioblastoma and was hypothesized to be a tumor suppressor gene. In contrast, CPE is elevated in colorectal cancer and plays a vital role in cell cycle regulation (Liang et al., 2013). CPE gene expression has been shown to be upregulated in OS samples when compared to healthy controls, indicating the role that CPE plays in the development of OS (Yang et al., 2014). Indeed, Fan et al. (2016) suggested that CPE is correlated with cell growth, tumorigenicity, migration, and invasiveness in OS cells.