5’-3’ exoribonuclease 1 (XRN1) is a ribonuclease localized in the cytoplasm that functions in mRNA metabolism and is found in messenger ribonucleoprotein (mRNP) complexes. The mouse and yeast homologs of XRN1 are Dhm2 and SEP1 respectively. In a glial cell line, XRN1 is induced by glial cell line–derived growth factor (GDNF) and associates with microtubules. XRN1 has also been identified as a candidate tumor suppressor gene in osteogenic sarcoma.