In mice, inactivation of the Rtel (regulator of telomere length) gene has been shown to cause chromosome breaks, fusions, and telomere loss. In addition, Rtel is required for telomere elongation. Therefore, the mouse Rtel gene regulates chromosome stability and telomere length. This gene is the human ortholog of the mouse Rtel gene, so its protein product may play similar roles in humans. Read-through transcription of this gene into the neighboring downstream gene, which encodes tumor necrosis factor receptor superfamily, member 6b, decoy (TNFRSF6B), generates a non-coding transcript. Multiple transcript variants encoding different isoforms have been described for this gene.