PNPO has been known to play a part in human epilepsy (Hoffmann et al., 2007; Khayat et al., 2008; Veeravigrom et al., 2015), and some research displayed that PNPO has played a role in the development of ovarian, breast, and colorectal cancers (Chen et al., 2017; Zhang et al., 2017; Ren et al., 2019). This evidence concerns the gene PNPO and colorectal cancer.