Ribosome-binding protein that acts as an inhibitor of mRNA translation by promoting ribosome inactivation (PubMed:30355441). Associates with the P- and E-sites of the ribosome and inserts a C- terminal helix into the mRNA exit channel to preclude translation (By similarity). {ECO:0000250|UniProtKB:P0DX19, ECO:0000269|PubMed:30355441}. This is the function of ENSG00000214706 (IFRD2, interferon related developmental regulator 2).