Mutations in tumor suppressors (such as TP53 and STAG2) and epigenetic regulators were occasionally observed in cystoscopy-negative urine samples of patients with a prior history of bladder cancer (2.3× enrichment in tumor-positive versus post resection negative cystoscopy samples); whereas oncogenes were rarely observed in post resection samples. The gene discussed is TP53; the disease is urinary bladder carcinoma.