Kinde et al. have shown that mutations in the telomerase reverse transcriptase (TERT) gene, which have previously been associated with urothelial carcinomas, can serve as biomarkers for this disease. The authors sequenced TERT mutations in 76 histologically well-characterized noninvasive urothelial carcinomas of various grades and found that all grades strongly associated with TERT mutations, which can be detected in urine. Importantly, the same TERT mutations were found specifically in patients who suffered relapse, but not in patients who remained free of carcinoma, indicating that TERT mutations might be a particularly useful marker for recurrent disease.