PTENP1 and cancer: The best studied non-coding transcript bearing the 3'UTR of a protein-coding gene is PTENP1. This pseudogene undergoes copy number loss in human cancers, this correlating with a decrease in levels of the tumor suppressor PTEN. It was proposed that PTENP1 exerts its function by sponging miRNAs, thus sustaining PTEN levels (Poliseno et al., 2010).