This family is found in Helitrons, recently recognised eukaryotic transposons that are predicted to amplify by a rolling-circle mechanism. In many instances a protein-coding gene is disrupted by their insertion.

1: Structure-based discovery and description of plant and animal Helitrons. Yang L, Bennetzen JL; Proc Natl Acad Sci U S A. 2009;106:12832-12837. PMID:19622734