RXRA and urinary bladder cancer: In light of recent reports speculating the importance of CD8+ T-cell infiltration into tumors for driving checkpoint blockade efficacy and the lack of responders to atezolizumab (anti-PD-L1) in the TCGA Cluster I luminal subtype16, we also evaluated PPARγ/RXRα activity (GLMnet74, refer to “Methods”) in MIBC from three cohorts (TGCA, bladder cancer meta-dataset and MD Anderson).