Telomeres must protect chromosome ends from being recognized and processed as double-strand breaks. Identification of the factors involved in end protection, and the mechanisms by which they "cap" chromosome termini, is crucial in understanding how the cell distinguishes between a double-strand break and a normal telomere end. Recent work has characterized the similarities and potential differences between the pathways utilized by multiple organisms in maintaining telomere ends. One unifying concept that has clearly emerged is that chromosome-end protection is necessary in maintaining genetic stability and preventing oncogenesis.