Abstract
Telomeres play an important role in cellular aging and cancer. Human telomeric DNA and RNA G‐rich sequences are capable of forming a four‐stranded structure, known as the G‐quadruplex. Such a structure might be important for telomere biology and a good target for drug design. This minireview describes the structural diversity or conservation of DNA and RNA human telomeric G‐quadruplexes, discusses structural views on targeting these G‐quadruplexes and presents some future challenges for structural studies.