Ready-to-use ELISA kits are available for the detection of 3'hExo, an alias of the protein, exoribonuclease 1. The official gene symbol is ERI1. The protein, with a mass of 40.1 kDa and length of 349 residues, is reported to be cytoplasmic and nuclear. It may be known by other names, including: histone mRNA 3'-exonuclease 1, histone mRNA 3'-end-specific exoribonuclease, 3'-5' exonuclease ERI1, 3' exoribonuclease, and 3'-5' exoribonuclease 1, and three prime mRNA exonuclease 1.