Recently described the functional relationship between the mRNAs produced by the PTEN tumor suppressor gene and its pseudogene PTENP1. PTENP1 regulates cellular levels of PTEN and can exert a growth-suppressive role and the PTENP1 locus is lost in several human tumors, including prostate and colon cancer. The gene discussed is PTEN; the disease is malignant colon neoplasm.