Previous studies have indicated that homozygous deletions of CDKN2A, a hallmark of advanced Uro tumors, correlate with progression and occur late in development.45 We did not observe this pattern, possibly due to difficulty to discriminate homozygous loss from single‐copy loss of chromosome 9, a universal event also in very early bladder tumors.42, 46 To definitively test the accuracy of inferring copy number alterations would require copy‐number data from a similar series of recurrences, which was not possible due to the quality and amount of DNA obtained. Here, CDKN2A is linked to urinary bladder neoplasm.