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). This evidence concerns the gene PTEN and cancer.