Contrary to current opinion, genomic instability is not the origin of cancer in patients with short telomere syndromes (STSs), researchers from the Johns Hopkins University School of Medicine reported April 2, 2023, in Cancer Cell. Instead, short telomeres appeared to cause memory T-cell dysfunction that increased the risk of a small number of tumor types in individuals with STS. Such syndromes can cause premature aging of different physiological systems.