Messenger RNAs lacking a stop codon (non-stop mRNAs) can arise from hydrolysis, premature termination, transcription error, or mutation. Lacking a stop codon, they do not recruit either of the mitochondrial termination factors (MTRF1, MTRF1L), cause ribosome stalling, and must be dissociated from the ribosome by a rescue factor, ICT1 (MRPL58) (Feaga et al. 2016, Kummer et al. 2021). Non-stop mRNAs are translated to the 3' residue of the mRNA, leaving an mRNA channel in the ribosome that is empty from the A site to the leading edge of the ribosome, but is filled from the P site to the trailing edge. The empty portion of the mRNA channel is recognized and filled by the C-terminal extension of ICT1 (Kummer et al. 2021). ICT1 then hydrolyzes the peptidyl-tRNA bond between the nascent peptide and the tRNA in the P-site of the ribosome. The ribosome is then recycled to 39S and 28S subunits through an uncharacterized mechanism. An additional ICT1 molecule is an integral subunit of the 39S ribosomal subunit (Richter et al. 2010).