(UroToday.com) Immune checkpoint blockade using PD-1 and PD-L1 targeting agents has proven clinical benefit in many metastatic carcinomas. However, identification of patients most likely to benefit has been difficult with most predictive biomarkers examined to date (including PD-1/PD-L1 status and tumor mutational burden) failing to demonstrate clinical utility. CDKN2A is one of the most commonly altered genes across human cancers and offers the potential as a predictive biomarker. However, currently available data are conflicting with respect to the association between CDKN2A alterations and ICBs. Thus, in a poster presentation at the 2021 American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU), Dr. Nassar and colleagues examine the effect of CDKN2A alterations on clinical outcomes in patients with urothelial carcinoma received immune checkpoint blockade (ICB).